$ perl -pe ‘s/\s//g’ tcm_creator.py> new
$ git checkout some-commit tcm_creator.py
$ perl -pe ‘s/\s//g’ tcm_creator.py> old
$ diff old new # should show no discrepancy
This worked for me. Entire file is flattened to a single long string.
IIF the whitespace change is only and always confined with a line i.e. no line splitting/joining , then perl -l -pe is more useful.
I have used this type of rules in many companies. My current set-up is —
Apply this rule after I submit a msg marked as Normal importance: defer delivery by 1 minute.
I wish there’s a “importance = A or B” condition.
https://docstore.mik.ua/orelly/perl3/lperl/ch09_05.htm shows
The part of the (haystack) string that actually matched the (needle) pattern is automatically stored in q[ $& ]
Whatever came before the matched section is in $` and whatever was after it is in $'. Another way to say that is that $` holds whatever the regular expression engine had to skip over before it found the match, and $' has the remainder of the string that the pattern never got to. If you glue these three strings together in order, you’ll always get back the original string.
— /m /s clarification:
Official doc says:
/m Treat the string being matched against as multiple lines. That is, change "^" and "$" from matching the start of the string’s first line and the end of its last line to matching embedded start and end of each line within the string./s Treat the string as single line. That is, change "." to match any character whatsoever, even a newline, which normally it would not match./ms, they let the "." match any character whatsoever, while still allowing "^" and "$" to match, respectively, just after and just before newlines within the string.strace -e trace=open myprogram can be used on a working instance to see where all the SO files are successfully located.
— Aug 2018 case: in QA host, I hit “error while loading shared libraries: libEazyToFind.so: … No such file or directory”
I can see this .so file so I used LD_LIBRARY_PATH to resolve it.
Then I get “error while loading shared libraries: libXXXXX.so: … No such file or directory”. I can’t locate this .so, but the same executable is runnable in a separate HostB. (All machines can access the same physical file using the same path.)
I zoomed into the HostB and used “ldd /path/to/executable”. Lo and behold, I can see why HostB is lucky. The .so files are located in places local in HostB … for reasons to be understood.
— May 2018 case:
The wording should be “cannot locate ….”
I fixed this error using $LD_LIBRARY_PATH
The *.so file is actually specified as a -lthr_gcc34_64 option on the g++ command line, but the file libthr_gcc34_64.so was not found at startup.
I managed to manually locate this file in /a/b/c and added it :
LD_LIBRARY_PATH=$LD_LIBRATY_PATH:/a/b/c/
I managed to split a huge g++ command line to about 300 lines… much more readable.
The trick:
Here’s the command
perl -pe "s/ -/ \\\\\n-/g" build1file.sh
–based on http://www.tushar-mehta.com/publish_train/xl_vba_cases/1205%20Outlook%20custom%20columns.shtml
IIf(Date()=int([Received]),Format([Received],”hh:mm”),IIf(Date()-[Received]<7,format([Received],”ddd m/d”),format([Received],”d mmm yy”)))
I name it “-myDT3” — 3 types of values
Q: can I share this custom column between Inbox/Deleted/Sent?
A: Unsuccessful try in 2010
Problem — unsortable
Solution — add the original Received field, but keep it razor thin
How to edit the formula: FieldChooser -> User-defined (usually empty) -> drag the new field in -> edit -> drag it out
#include <fstream>
std::string const & get_command_line() {
static std::string ret;
if (ret.empty())
try{
std::string path="/proc/" + std::to_string((long long)getpid()) + "/cmdline";
std::cerr<<"initializing rtsd parsername from "<<path<<" ..\n";
std::ifstream myfile(path);
if (!myfile) return ret;
getline(myfile, ret);
}catch(...){
}
return ret;
}
Useful in coding tests and in project
// Usage 1
(success ? cout << "Apportionment succeeded: " :
cerr << "Apportionment failed: ")
<< msg <<endl;
// Usage 2 in my own code
(isLeft? parent.left: parent.right) = newChildNode;
Scenario — On my vertical monitor I want two windows A and B stacked; on my other monitor I want one big window; total 3 windows.
Solution —
Note to show windows side by side there are many options like winKey and snap
Areo Snap (https://www.howtogeek.com/181681/4-hidden-window-management-tricks-on-the-windows-desktop/) worked on my Win10:
See also post on csv string parse…
For a longer delimiter, you may need string.find()
https://github.com/tiger40490/repo1/blob/cpp1/cpp/binTree/serialize_bbg.cpp has my own tested solution parsing individual tree node details from a stringstream
ifstream f1(fileName.c_str());
string line;
while(getline(f1, line)){
for(int i=1; ;++i){
int pos = line.find_first_of("\t");
string token = line.substr(0,pos);
cerr<<i<<" : " <<token<<endl;
if (line == token) break; //there's no more tab in the line
line = line.substr(pos + 1);
}
}
///// a simpler method:
istringstream lineStream("denmark sweden india us"); //consecutive spaces are Not treated as one
string outputToken;
int main(){
while (
getline(lineStream, outputToken, ' ')) // <-- the only thing to remember
cout << outputToken << endl;
}
Still no definitive answers…
In one machine, q(ulimit -c) returns 0 meaning suppressing core files. I had to run q(ulimit -c unlimited) to get my core files generated.
Survival tip — Alt-t gets to Settings, if you need to unhide …
Motivation — most monitors are too “thin”, so the bars take up vertical space.
back to last page — ctrl-leftArrow
close current tab — ctrl-w
First learn the keyboard accelerator to select current line.
Remember shift-HOME selects back till beginning; shift-END selects till the end.
HOME then shift-END
END then shift-HOME
[[ $(hostname) == "rtdevfrh"* ]] && isUK=1 [[ -z $isUK ]] && echo not in UK [[ -n $isUK ]] && echo in UK
https://www.howtogeek.com/howto/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/ is a 2017 article.
The mklink command can create both hard links (known as “hard links” in Windows) and soft links (known as “symbolic links” in Windows).
On Windows XP, I have used “Junction.exe” for years, because mklink is not available.
NIC — There’s another blog post https://bintanvictor.wordpress.com/2018/03/19/discover-nic-my-machine-lspci/
$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15
Thread(s) per core: 1
Core(s) per socket: 8
CPU socket(s): 2
NUMA node(s): 2
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 20480K
$ less /proc/cpuinfo|egrep 'core id|processor' # on the same machine shows
16 “processors”, but #0 and #1 have the same core-id! Total 8 core-id values. I think this is because in each (of two) socket, there are 8 cores with unique core-id values.
dmesg | grep rocessor # doesn’t work any more
dxdiag # windows
dxdiag /t c:\deldel.txt
find “CPU” c:\deldel.txt # copy-paste may not work
print obj1 # by default shows limited content like
<testcases.multitest.result.Result object at 0x7fe7f08fc810>
It’s more useful to see the source code of the obj1’s type definition like “Result” in this case. Here’s how
print testcases.multitest.result.__file__ # assuming …result is a module
myVec.insert(myVec.begin() + INTEGER_OFFSET, DATA);
–Use stringstream:
stringstream tmpPath;
tmpPath.str(“”); //set to empty string
tmpPath<<tmpFolder << tmpCount++;
cout<<tmpPath.str()<<endl;
I prefer one single full-feature solution that’s enough for all my needs. The os.system() solution is limited. The subprocess module is clearly superior. One of the simplest features is
>>> subprocess.call([“ls”, “-l”])
If you need redirection and background, then try the single-string version
>>> subprocess.call(‘ls /tmp > /tmp/a.log &’, shell=True) # output goes to STDOUT, hard to capture
https://github.com/tiger40490/repo1/blob/bash/bash/thisScriptDir.sh is latest tested solution
fullpath="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
echo fullpath is $fullpath # fairly reliable one-liner, provided the script itself isn't a symlink
https://github.com/tiger40490/repo1/blob/bash/bash/vimrc has some tricks including how to make vim remember last edit location.
–paging commands in vi and less
— q[less] searching feature
[3/4] means vi receives 3 keystrokes; we hit 4 keys including shift or ctrl …
[3/4] means vi receives 3 keystrokes; we hit 4 keys including shift or ctrl …
–“split” solution by Deepak M
vi file1 # load 1st file
–the q( :e ) solution
vi file1 # load 1st file
–editing 3 or more files
q(:n :N ^) always shows the current filename in status bar:)
https://stackoverflow.com/questions/2064692/how-to-print-function-pointers-with-cout says just cast to void pointer
"cout << (void *)pf is " << (void *)pf << endl;
printf("printf(\"%%p\", pf) is %p\n", pf);
I struggled with subshell but now I prefer this pushd technique. Useful not only in shell scripts:
pushd dir1
runCommand
popd
Challenge (common problem for developers) : locate a breaking commit in a long history
More than once, I have found great value in checking out two copies from the same branch. Need to compare the two directories recursively.
diff -w -r -x CVS -x shared -x lib -x *.o -x '*.b4vtanedit*' aquis aquis1 | less -E
—to convert from epoch to HHMMSS:
https://github.com/tiger40490/repo1/blob/cpp1/cpp/88miscLang/convertEpochInt.cpp
—to convert current time to int epoch number:
https://github.com/tiger40490/repo1/blob/cpp1/cpp/88miscLang/convertEpochInt.cpp
—epoch timestamp is typically in seconds
Tested but is too hard to remember. Better use the getline() trick in https://bintanvictor.wordpress.com/2017/11/05/simplest-cway-to-split-string-on-custom-delimiter/
struct comma_is_space : std::ctype<char> { //use comma as delimiter
comma_is_space() : std::ctype<char>(get_table()) {}
static mask const* get_table() {
static mask rc[table_size];
rc[','] = std::ctype_base::space;
return &rc[0];
}
};
istringstream iss(line);
iss.imbue(locale(cin.getloc(), new comma_is_space));
Note the mismatched args to the comparitor functions.
(I was unable to use a functor class.)
std::vector<Tick const*> vec;
int target;
bool mylessFunc(Tick const * tick, unsigned int target) {
//cout<<tick->ts<<" against "<<target<<endl;
return tick-ts < target;
}
lower_bound(vec.begin(),vec.end(),target, mylessFunc);
bool mygreaterFunc(unsigned int target, Tick const * tick){
//cout<<a->ts<<" against "<<target<<endl;
return tick->ts > target;
}
upper_bound(vec.begin(),vec.end(),target, mygreaterFunc)
I found WordPad RTF files a good middle ground between ascii text and MSWord files.
Verdict —
//size_t or int
int endpos = word.find_last_not_of(” “);
if (endpos < string::npos) word = word.substr(0, endpos1);
map<int, int>{{32,1}}
Confession — I’m a laggard on adopting new applications. Ascii text files are my default choice.
I think OneNote is suitable for office use —
🙂 save screenshots, but I can do the same in outlook
🙂 add notes anywhere on the doc, to make more visual presentation/documentations. However, for personal note taking I won’t need this feature.
This is related to q[cannot open shared object file] abc.so
See https://amir.rachum.com/blog/2016/09/17/shared-libraries/#rpath-and-runpath for the RUNPATH
q(objdump) can inspect the binary file better than q(ldd) does.
q(ldd) shows the final, resolved path of each .so file, but (AFAIK) doesn’t show how it’s resolved. The full steps of resolution is described in http://man7.org/linux/man-pages/man8/ld.so.8.html
q(objdump) can shed some light … in terms of DT_RUNPATH section of the binary file.
I like “typing tutors”
I also like a family of alias like nx- nx, nx.
| allowed in alias | no shift | ||
| -(dash) | good | good | |
| , (comma) | good | good | |
| . (dot) | good | good | |
| + (plus) | good | good | |
| ! | good | bad | |
| = (equals) | bad | ||
| backtick | bad | ||
| / or \ | bad | ||
least amount of code
struct stat buffer; stat(m_secInfoFileName.c_str(), &buffer); cerr<<localtime(&buffer.st_mtime) ->tm_mday<<endl; cerr<<localtime(new time_t(time(NULL)))->tm_mday<<endl;
netstat has -p flag
netstat -pln |grep 40493
https://github.com/tiger40490/repo1/blob/cpp1/cpp/array/minCostPartition_Flex.cpp shows the vector ctor vector(sz, defVal)
I often need a manual switch in source code. I can make a one-char change to turn on/off a block.
if (0) and if (1) is good enough in c/python. Java must use if(true)
In bash, I now use
Purpose: temp reminders
| on top | visibility | hide | folder tree | ||||
| sticky note | y | good | no 😦 | no | |||
| outlook note | y | good | yes | yes 🙂 | |||
| paper note | y | best | yes |
Hi guys, thanks to all your help, I managed to locate the very first trading session message in the raw data file.
We hit and overcame multiple obstacles in this long “needle search in a haystack”.
Solution: read the exchange spec. It should be mentioned.
Solution 1: xxd -c 999999 raw/feed/file > tmp.txt; grep $needle tmp.txt
The default xxd column size is 16 so every 16 bytes output will get a line break — unwanted! So I set a very large column size of 999999.
Solution 2: in vi editor after “%!xxd -p” if you see line breaks, then you can still search for “ec\_s*3d”. Basically you need to insert “\_s*” between adjacent bytes.
Here’s a 4-byte string I was able to find. It span across lines: 15\_s*00\_s*21\_s*00
Solution: remove each file successively, starting from the later hours, and retest, until the needle stops showing. The last removed file must contain our needle. That file is a much smaller haystack.
o one misleading info is the “9.30 am” mentioned in the spec. Actually the message came much earlier.
o Another misleading info is the timestamp passed to my parser function. Not sure where it comes from, but it says 08:00:00.1 am, so I thought the needle must be in the 8am file, but actually, it is in the 4am file. In this feed, the only reliable timestamp I have found is the one in packet header, one level above the messages.
Solution: find a longer and more unique needle, such as the SourceTime field, which is a 32-bit integer. When I convert it to hex digits I get 8 hex digits. Then I flip it due to endian-ness. Then I get a more unique needle “008e0959”. I was then able to search across all 14 data files:
for f in arca*0; do
xxd -c999999 -p $f > $f.hex
grep -ioH 008e0959 $f.hex && echo found in $f
done
o If you convert a long byte array to hex and print without whitespace, you could see 15002100ffffe87600,but when I added a space after each byte, it looks like 15 00 21 00 ffffe876 00, so the 3rd byte was overflowing without warning!
o If you forget padding, then you can see a lot of single “0” when you should get “00”. Again, if you don’t include white space you won’t notice.
Solution: I have worked out some simplified code that works. I have a c++ solution and c solution. You can ask me if you need it.
Tip: If sequence number is in the feed, you would probably spot a pattern of incrementing hex numbers periodically in the hex viewer.
set -o multiline
Doesn’t work on bash but i don’t know if bash has this problem.
–Challenge: scan a c++ codebase for a given func name
See also the task in Outlook!
–A related challenge: suppose you have the definition of a function, how do you see all the callers?
Csmi.C: In static member function ‘static csmiparser::Csmi& csmiparser::Csmi::getInstance()’:
Csmi.C:14: warning: ‘__comp_ctor ’ is deprecated (declared at /home/vtan/tp/plugins/xtap/csmi/include/Csmi.h:33)
ftp:username@hostname
System prompted and saved my password 🙂
–Create shortcut on desktop
Copy putty.exe into c:\windows
http://www.htpcbeginner.com/putty-shortcut-to-saved-session/
“putty -load ficsinapd01 -l vtan7”
–adding the shortcut to StartMenu
I was able to copy the shortcut to some part of my startMenu
A new solution — I created a start menu item containing
“\path\to\putty -load Session3”
du -csxPBM * | sort -n
du -cks * |sort -n |tail
du -h –max-depth=1 | tee ~/diskUsage2.log
For cpu, there’s another blog post https://bintanvictor.wordpress.com/2011/11/20/q-discover-cpu-count-my-machine-linuxwin/
lspci | grep -i ‘ethernet’ #shows
ifstream myfile((tmpDir.str()+"_config").c_str()); if (myfile) // file may not exist myfile>>packetDumpLimit;
q(more) dumps each filename before the content 🙂 Useful when you need to copy paste multiple file contents to an email.
struct timeval timeValNow;
gettimeofday (&timeValNow,NULL); //populates the struct
struct tm * ptm = gmtime( &timeValNow.tv_sec );
timestampNow.str("");
timestampNow<<ptm->tm_year +1900;
timestampNow<<setfill('0')<<setw(2)<<ptm->tm_mon+1;
timestampNow<<setw(2)<<ptm->tm_mday<<'-';
timestampNow<<setw(2)<<ptm->tm_hour<<':';
timestampNow<<setw(2)<<ptm->tm_min<<':';
timestampNow<<setw(2)<<ptm->tm_sec<<'.';
timestampNow<<setw(6)<<timeValNow.tv_usec;
I think the simple “%f” may just work, without any numeric specifiers.
/Reset|Msg_|Warn_|Primary|Secondary
[3/4] means vi/less receives 3 keystrokes; we hit 4 keys including shift or ctrl …
–search can fail with super-long lines. See also http://www.greenwoodsoftware.com/less/bugs.html
https://superuser.com/questions/113039/less-quickly-jump-to-line-number-in-large-file
5% .. is extremely useful.
alias diff=’diff -W $(( $(tput cols) – 2 ))’ # make use of full scren width
tput cols # does change as screen resizes 🙂
I prefer the controlPanel rather than the Settings screen… ControlPanel can show all the apps without the messy categories. Also, the winKey->search is unreliable when searching for a controlPanel app. Once again, Microsoft did a sloppy job.
To change any setting, I believe we always need one of those apps. Windows GUI try to hide the boundaries between the apps, and make it very very confusing.
https://en.wikipedia.org/wiki/Caret_notation explains the caret notation.
q(less) and many other unix tools prints “funny characters” in caret notation.
MenuBar -> File -> left pane -> Info -> far right -> OpenFileLocation
Other posts mention this topic as part of bigger discussions. This post is more focused.
printf "\nContinue? [ y /any_other_key] " ### easier than echo -en unset REPLY; read $REPLY [ "$REPLY" = "y" ] || return ### single equal sign! unset REPLY ### remove any residual effect
Suppose you know where the line break, if any, would be.
/abcd\_s*efgh — Finds abcd followed by any whitespace or newlines then efgh.
–q(time) command
output can be a bit confusing.
Q: does it work with redirection?
–$SECONDS variable
See http://stackoverflow.com/questions/19772/cmd-exe-replacement
–console
not yet tested
http://www.maketecheasier.com/console-2-windows-command-prompt-alternative/
http://www.makeuseof.com/tag/sick-command-prompt-windows-7-upgrade-console/
–%% wishlist
copy/paste
edit command history
shell integration
—
🙂 conEmu can search throughout console output
🙂 conEmu here
🙂 conEmu double-click to select text
🙂 console2 requires research (no time!) on tweaking to fix copy/paste.
🙂 console2 here
😦 PowerCmd requires admin right every time to use
for file in `find . -type f`; do
file $file |grep CRLF
[ $? -eq 0 ] && dos2unix $file
done
BeyondCompare3 can compare 2 “deep” directory trees. To make it compare file contents, you need to select all files (Ctrl-A) then hit the button “Compare Content”.
Other diff tools? No experience.
— based on http://www.yolinux.com/TUTORIALS/LinuxTutorialAdvanced_vi.html
Any line can be “Book Marked” for a quick cursor return. Type the letter “m” and any other letter to identify the line. This “marked” line can be referenced by the keystroke sequence “‘” and the identifying letter.
Example: “mt” will mark a line by the identifier “t”. “‘t” will return the cursor to this line at any time. I prefer mm and ‘m
A block of text may be referred to by its marked lines. i.e.’t,’b
— Not yet tested:
your_command | ts
What if your_command was started by someone else?
Tail -f the.log |ts
–Tested:
tail -f ,trash.log | perl -MPOSIX -pe ‘print strftime (“[%H:%M:%S] “, localtime)’
I will mostly talk about MSVS but will mention linux build too.
The common methods to set up the dependency, all done inside project BB
1) specify project dependency in MSVS
2) define include path to cover the header from AA
3) define library path to cover the object file from AA
Suppose project BB uses “things” in project AA. Say a file in BB #-includes a header in AA. I think it's not necessary to have any. This is important when you debug the dependency. You may fail to find any trace of the dependency in any of those places. The file in BB can simply #-include the full/relative path to the header from AA.
http://blogs.msdn.com/b/vcblog/archive/2010/02/16/project-settings-changes-with-vs2010.aspx describes project reference vs project dependency….
….. much more to say.
readlink -f {any file such as ../scripts/mvn.sh}
Usable in sh-script or interactively
See also http://stackoverflow.com/questions/242538/unix-shell-script-find-out-which-directory-the-script-file-resides
2) FIND?
Note Search-string is case sensitive.
!Must double-quote search-string. (Single quote doesn’t work.)
ftype | find “Python”
assoc | find “pyw”
label: timeSaver
less -> vi : “v”
tail -> less? Nothing found.
–from within vi,
switch to readonly mode: qq( :se ro )
switch to readwrite mode: qq( :se noro )
—less to replace tail -f
$ less /var/log/messages
Common-mode -> Follow-mode: F
Follow-mode -> Common-mode: Ctrl-c
To start less in the Follow-mode,
$ less +F /var/log/messages
http://stackoverflow.com/questions/8220256/bash-color-escapes-codes shows
less -R your.file
Easy in win-xp- – Create an item on the start menu. The item is a link to the tmp file.
Win10
To use,
Pretty quick!
Q: how to make the search more precise, by making the item names more unique?
Win7?
–Solution 3: I managed to pin Notepad++ to startMenu. Then the cascading menu “under” Notepad++ shows some recent files. I managed to pin one of them. Then I could use keyboard alone to hit that file by first letter.
–solution 1:
On win7, I had to name the file something like c:/temp/tmppp.txt. Then place a shortcut on Desktop outside any myShortcuts\ folder. Then right-click -> properties -> shortcut.
Ineffective when notepad++ is already running (possibly minimized to tray…) So the workaround is Alt-F4 to kill notepad++ then use the shortcut key
–Solution 2 (broken in Morgan): drag shortcut “pin to start menu”
1. Open mswe and locate the file
2. Drag the file towards the start button until “pin to start menu”
3. Pin it to top of the list
4. From now on, we can wake up the start menu then arrow-down, blindfold
For each feature, let’s verify it and give links to only good web pages
Even after the “parent shell” of the screen is killed, the screen is still alive and “attached”!
–[ Essential] How to tell if I’m in a screen
http://serverfault.com/questions/377221/how-do-i-know-im-running-inside-a-linux-screen-or-not
–[ Essential] reattach
http://www.gnu.org/software/screen/manual/screen.html#Invoking-Screen
–feature
keep a session alive after I log out. Almost like windows mstsc.exe
–feature – log the screen output
See http://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/
The log file is created in the current dir …
–feature – Run a long running process without maintaining an active shell session
See http://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/ — using top as a long command
–(untested) feature – monitor a screen for inactivity as a sign of job done.
See http://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/
–http://stackoverflow.com/questions/12407800/which-comment-style-should-i-use-in-batch-files
set "var=3" %= This is a comment in the same line=%dir junk >nul 2>&1 && %= If found =% echo found || %= else =% echo not found
The leading = is not necessary, but I like if for the symmetry.
There are two restrictions:
1) the comment cannot contain %
2) the comment cannot contain :
append.bashrc.txt
<![CDATA[ << ______________end_of_comment_1________________ J4 etc: to reduce section spacing modified [11 Jan 2007] ______________end_of_comment_1________________ [ -z “$(echo $- | grep i)” ] && return # # # # # # # # # # # # # # # # # # # # <> should be first # # # # # # # # # # # # # # # # # # # # # # # export PS1=’\n\s!\! \u@\h [ \t \d ] \w/ \n\$ ‘ export EDITOR=vi # primarily for sqlplus export EXINIT=” :se nu | :map v :w ” # must export LESS=”–ignore-case” export TMOUT=987654; [ $root ] && export TMOUT=100600 HISTSIZE=900 set -o emacs set +o nounset export PATH=/usr/xpg4/bin:$PATH; [ $(id -u) = 0 ] && root=yesur set +o noclobber; [ $root ] && set -o noclobber sav=$LOGNAME # # PAGER and TERM issues: # # “vt100 less -E” is ok on linux # TERM ‘linux’ breaks vi in gnome-terminal; ‘linux’ imperfect for solaris # for “less”, -E needed for dir-viewing, file-viewing but affects man # export PAGER=more export PAGERE=more if [ -z “$(which less |grep ‘^no less’)” ]; then export PAGER=”less” # breaking some x terminals but ok in “console” export PAGERE=”less -E” # -E needed for dir-viewing, file-viewing but affects man fi echo TERM=$TERM initially export TERM=vt100 # ‘linux’ breaks vi in gnome-terminal; ‘linux’ imperfect for solaris # # # # # # # # # # # # # # # # # # # # # # # # <># # # # # # # # # # # # # # # # # # # # # # # alias killthem=”perl -pe ‘s/^\S+(\s+\d+).*/\1/ or s/.*//’|xargs -pt kill” # p str1 | killthem # alias killthem=”perl -pe ‘s/\S+(\s+\S+).*/\1/s’|xargs -pt kill” # p str1 | killthem # sortable : alias %=cd_l # typing trainer alias ..=’cd_l ..’ alias cp=’cp -i’ # defuse alias egi=’export |grep -i’ alias h=history alias hgi=”history |grep -i” alias j1=”fg %1″ alias j2=”fg %2″ alias m=$PAGERE alias mv=’mv -i’ # defuse alias p=ps_grep alias path=” echo \$PATH |perl -pe ‘s/:/\n/g’ |sort -u|m ” alias rm=myrm alias s=’ source $HOME/.bashrc ‘ # .profile absent alias t=’l -t’ alias top=’prstat’ # # # # # # # # # # # # # # # # # # # # # # # # <> difficult to sort # # # # # # # # # # # # # # # # # # # # # # # cd_l(){ [ $# -eq 0 ] && l && return [ -n “$( file $* | grep directory )” ] && cd $* && l && return [ -n “$( file $* | perl -ne ‘print if /text|script/’ )” ] && m $* && /bin/echo “\n\n” && l $* } d(){ [ $# -ne 0 ] && cd $* [ `pwd` = ‘/’ ] && target=/ && echo I am in / echo “In MB :” eval du -ks * |sort -n|perl -pe ‘s|^(\d+)|$1/1000|e’ } g(){ # bug with g -v pattern=$1; shift cmd=” grep -i \”$pattern\” $* ” /usr/bin/printf ‘%s\n’ “cmd=__$cmd __” eval $cmd |$PAGERE } l(){ # can’t be completely replaced by ‘cd_l’ or ‘]’, because “cd_l -tr dir1″ is confusing and should be avoided /bin/ls -alFs $* |$PAGERE } myrm(){ cmd=”mv -i $* /var/tmp/$sav/ ” /usr/bin/printf ‘%s\n’ “cmd=__$cmd __” eval $cmd } ps_grep(){ ## cmd1=’/bin/ps -ef’ # truncation risk # ps auxwww : inconsistent for root vs non-root cmd1=’/usr/ucb/ps auxwww’ # |grep -v grep — no cos some real commands contain grep for f in $*; do cmd1=”$cmd1 | g $f” done eval $cmd1 } sav(){ suffix=$RANDOM$(date +”%H%d%b”) # to avoid misleading readers,make the suffix ambiguous for f in $*; do f=$(echo $f|perl -pe ‘s|/$||’) # sav dir/ b=`basename $f` ( cd `dirname $f` ; tar cf – $b | (cd /tmp; tar xpf -) /bin/mv -i /tmp/$b $b.b4${sav}edit$suffix [ -d $f ] && opt=’ -d’ eval ls -lt $opt $b* ) done } # # # # # # # # # # # # # # # # # # # # # <>, an exercise in grouping # # # # # # # # # # # # # # # # # # # # # # # exa(){ #testing: exa -t ss ~/.ssh local ops while is_opt=`echo $1 |perl -ne ‘print if /^-/’ ` && [ “$is_opt” ]; do ops=”$ops $1″; shift done if [ $# -eq 1 ]; then fullpath=$1 shortname=`echo $1|perl -pe ‘s|/$||;s|^.*/||’ ` else fullpath=$2 shortname=$1 fi [ -x $fullpath ] || return # export “$shortname”=”$fullpath” set $shortname=”$fullpath” prj=”$fullpath” alias “$shortname”=”cd $fullpath;l $ops” alias prj=$shortname # USE MORE } exa /tmp/ exa /etc # # # # # # # # # # # # # # # # # # # # # <># # # # # # # # # # # # # # # # # # # # # # # add_path(){ [ -r $1 ] || return [ “$(echo $PATH|grep :$1)” ] && return # check world write perm, esp for root PATH=$PATH:$1 } set_manpath(){ # very slow on some systems. Run this when u need it. for d in `ls -d /[uo]*/*/man /[uo]*/*/*/man /[uo]*/*/*/*/man`; do export MANPATH=$MANPATH:$d done } set_path(){ add_path /usr/sbin add_path /usr/bin add_path /sbin add_path /usr/local/bin add_path /usr/cluster/bin add_path /usr/openwin/bin/ add_path /usr/ucb add_path $ORACLE_HOME/bin add_path /usr/sfw/bin # pre-installed add_path /opt/csw/bin [ $root ] && return add_path . add_path $HOME/bin } set_path ]]>
tip: print someStr, someInt # avoids str(someInt)
tip: print ‘ ‘.join([str1, str2, str3]) # packed tighter than ..
print [str1, str2, str3] # has space in between
print # empty would print a newline
for %i in (*.jar) do @jar tvf %i | find “TXDocument.class”
for %i in (java.exe) do @echo. %~$PATH:i
pushd myjava & java -Djava.rmi.server.codebase=http://10.203.111.166:20380/murex.download.guiclient.download -classpath %CP% com.ocbc.quest.murexgateway.MurexServer 19673 & popd
This DOS command line does 3 things
1) temporarily chdir into “myjava” folder and
2) run a (long) java command line, and then
3) restore the previous directory.
Actually, the java process blocks the script forever. If you use ctrl-C to terminate the blocking java process, you still get back into the previous directory J
See
If you don’t satisfy all the conditions, then you get “0” as the dummy line number.
1) deploy the pdb files of all of my own DLL and EXE. If you put in some of them you may see some line numbers.
2) pdb file and the DLL/EXE should come from the same build. Version mismatch will trigger no exception. Just “0”.
Obviously you need something like this to see any logging at all —
log4net.Config.XmlConfigurator.Configure();
<![CDATA[ private static String getMetaData4Obj(Object o) { return getMetaData4Class(o.getClass()); } private static String getMetaData4Class(Class clazz) { String className = clazz.getName(); className = className.replace(“.”, “/”); className += “.class”; URL location = clazz.getClassLoader().getResource(className); return clazz + ” loaded from ” + location; } ]]>
From a Method object you can get the host Type object.
From a Type object you can get the host Assembly object.
From Assembly object you can get the physical assembly file.
1) (tested) Assembly.GetExecutingAssembly().Location; // gives the dll fullpath
1c) new T().GetType().Assembly; //returns the Assembly object. Works even though T is a template dummy type!
2) Process.GetCurrentProcess().MainModule.FileName
3) AppDomain.CurrentDomain.BaseDirectory; // Similar to 1)
My suggestion — First find a “safe” character that’s guaranteed not to show up in the original string, like “_”. Replace all back slashes. Then proceed.
Problem with backslashes is the unnecessary complications. Here I want to match “one-or-more backslashes”. In the end I need to put 4 bachslashes in the pattern to represent that “one”.
var ret = Regex.Replace(@”any number of\\\backslashes”, “(.+\\\\+)?(.+)”, “$1 – $2”);
Alternatively, I could use @ to reduce the complexity @”(.+\\+)?(.+)”
Disappointingly the @ does a partial job. We still need 2 strokes — Confusing! I’d rather just remember one simple rule and avoid the @ altogether
Errorlevel is like a “dynamic readonly” whiteboard (NOT an environment variable — see below). The whiteboard is wiped clean and overwritten by DOS after each command executed. This happens whether you run the commands interactively or in batch using *.bat files.
You can say this whiteboard shows _transient_ values. For a crude analogy, consider the variable behind LED temperature display. It keeps changing.
If you want to capture a particular transient value of this object, save it *immediately* in your own variable (before echoing %errorlevel%). See http://www.coretekservices.com/2012/06/28/dos-batch-file-error-level-checking-tricks/
Q: What’s %ERRORLEVEL% vs bare ERRORLEVEL ?
A: %ERRORLEVEL% will expand into a String representation of the current value of ERRORLEVEL, provided that there is not already an environment variable with the name ERRORLEVEL, in which case you will get its value instead.
A: To see the value, you must use %xxx%. Consistent with other DOS variables such as %OS%
Go into any folder. Click into the search bar on top of the message list. You will see a new “search” ribbon added.
http://superuser.com/questions/102233/how-to-go-to-remote-directory-in-cygwin explains
Windows' builtin pushd will auto-mount the share to a temporary drive, which is accessible from Cygwin.
C:> pushd \myserverphotosoriginal
Z:original>
uuencode path/to/file file_name2display | mailx -s “subject1” bin.tan@xxx.com
…any body text….
^D # to end keyboard input
alt + F4 — close active window
winKey + Break — to see environment variables
for %i in (gcc.exe) do @echo %~$PATH:i
This shows where exactly the executable is loaded from.
(Tested in DOS)
–in win7, try “where”
[ -f unixfile ] && rm unixfile || print “unixfile was not found, or is not a regular file” — to be tested
Finally, multiple commands can be executed based on the result of command1 by incorporating braces and semi-colons:
command1 &
If the exit status of command1 is true (zero), commands 2, 3, and 4 will be performed.
See other post(s) on exit status
Simple and clean — $ref = \@existingList
Avoid the other tricks until you find your footing.
\(100, 9900,2500) is misleading.
Anonymous arrayref is confusing.
A common perl-n/perl-p challenge is to sum over loops. Solution is the END{} block.
This example below is from http://www.theperlreview.com/Articles/v0i1/one-liners.pdf —
ls -lAF | perl -ne ‘ next if /^d/; $sum += (split)[4]; END{ print $sum } ‘
(I guess this sums up all the files’… sizes?)
Note you need not pre-declare $sum as a static-local (in C lingo). I guess it’s static-local by default.
This post focuses on one question:
Q: was previous cmd successful@@
A: (based on [[ teach yourself shell programming ]])
if [ $? -eq 0 ] ….
Background: i wasn’t sure if my own solutions were reliable. Now this author also believed in [ $? -eq 0 ]
cmd1 && … # tests 0. [[ learning the bash shell ]]
cmd1 || .. # tests 0.
“0 means OK” is standard convention. A script or command can break the convention, but you are allowed to assume no one does.
<![CDATA[ /** based on http://javablog.co.uk/2008/07/12/logging-with-javautillogging/* Class name is mentioned in C:\Program Files\Java\jre1.6.0_06\lib\logging.properties */ public class JDKLoggingForamtter extends SimpleFormatter { private final String lineSeparator; public JDKLoggingForamtter(){ lineSeparator = java.security.AccessController.doPrivileged( new sun.security.action.GetPropertyAction(“line.separator”)); } @Override public synchronized String format(LogRecord record) { String sb = super.format(record); String lineNum = getEclipseFormat(); return sb.replaceFirst(lineSeparator, ” ” + lineNum + lineSeparator); } /** * Returns caller location information in eclipse format eg (Filename.java:23) * WARNING Generating caller location information is extremely slow. * It's use should be avoided unless execution speed is not an issue. * * @return the eclipse format */ private static String getEclipseFormat() { // getStackTrace can be expensive StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace(); String upstairs = “”; int lineNumber = 0; //StringBuilder sb = new StringBuilder(); // Here is an example of the typical stack trace we get back. // level 0 (Thread.java:1436) getStackTrace // level 1 (CustomFormatter.java:139) getFileLineNumber // level 2 (CustomFormatter.java:128) format // level 3 (StreamHandler.java:179) publish // level 4 (ConsoleHandler.java:88) publish // level 5 (Logger.java:458) log // level 6 (Logger.java:480) doLog // level 7 (Logger.java:503) log // level 8 (YourCodeHere.java:26) someMethod if (stackTrace.length >= 9) { String fileName = stackTrace[8].getFileName(); lineNumber = stackTrace[8].getLineNumber(); // Each of these calls back into logger.logp with the appropriate // level and message. This adds one extra level to the stack trace // logger.finest(“finest message”); // logger.finer(“finer message”); // logger.fine(“fine message”); // logger.info(“info message”); // logger.warning(“warning message”); // logger.severe(“severe message”); // logger.entering(“SomeClass”, “aMethod”); // logger.exiting(“SomeClass”, “aMethod”); // logger.exiting(“SomeClass”, “aMethod”, “returnval”); // logger.config(“config message”); // // Here is an example stack trace from a call to exiting // level 0 (Thread.java:1436) getStackTrace // level 1 (CustomFormatter.java:139) getFileLineNumber // level 2 (CustomFormatter.java:128) format // level 3 (StreamHandler.java:179) publish // level 4 (ConsoleHandler.java:88) publish // level 5 (Logger.java:458) log // level 6 (Logger.java:480) doLog // level 7 (Logger.java:623) logp // level 8 (Logger.java:938) exiting // level 9 (YourCodeHere.java:27) someMethod // // We could check the name of the method we are in and only go one level deeper // if it is one of “finest”, “finer”, “fine”, “info”, “warning”, // “severe”, “config”, “entering” or “exiting” but that would be too much trouble. // If the stack is in Logger.java and we can go one level deeper – do it. if (stackTrace.length >= 10 && “Logger.java”.equals(fileName)) { fileName = stackTrace[9].getFileName(); lineNumber = stackTrace[9].getLineNumber(); } if (stackTrace.length >= 10){ upstairs = ” = 11){ upstairs += “
java -classpath “C:/jars/*” your.main.class
Without double quote, you get funny errors. No such problem on linux.
String formatNumber = “%10.4f “; //good if numbers don't need
more space than “xxxx.yyyy”
String formatHeader = “%10.10s “; //fixed 10 char columns,
truncating if necessary
“%.8s” — will copy only first 8 characters of the original string.
q(grep -r –color) is a simple solution but I still worry about lack of control.
# use grep inside perl, without xargs find . -type f|perl -nle 'print "$_ --\n$a" if /\.(C|h)/ and $a=qx(grep -i "btmodels" "$_") ' find . -type f|perl -nle 'print "$_ --\n$a" if !/\.git/ and $a=qx(grep -i "btmodels" "$_") '
—-windows
MSWE search is unreliable for full-text search. Ditto for MSVS search. Don’t waste time on them!
Try notepad++. You can click the search result, and get keyword highlight, like in google!
Try findstr in http://stackoverflow.com/questions/698038/windows-recursive-grep-command-line
new PrintWriter(new FileWriter(fileNameStr, isAppend), isAutoFlush);
defeated candidates:
* PrintStream is nicely unbuffered but not idea for text output.
* the nested FileWriter thing is … sadly buffered.
Tortisesvn has s nice recursive check-for-modifications. It shows my
local changes, in an offline fashion.
No such feature in subclipse.
Using exceed, it can be a challenge to set up copy-paste between win32
and X windows. I know 2 options.
Note I always enable auto-copy-x-selection and
auto-paste-to-x-selection.
— option: X-selection-page -> X Selection Associated With Edit
Operations set to Primary —
Lesson? “Primary” is the default. In this mode, don't use the xwin
context-menu.
* Simple-Select (without middle-button or context menu) to copy from
unix, paste to win32? Yes
* Simple-Select (without middle-button or context menu) to copy from
unix, middle-button to paste to unix? yes
* Select from win32, middle-button to paste in unix? Yes
* Select from win32, context-menu->edit->paste in unix? no
— option: X-selection-page -> X Selection Associated With Edit
Operations set to Clipboard —
This is suggested on some webpage. It also enables copy-paste between
unix and windows.
In most cases, I can replace StringBuilder with a Formatter, but of course Formatter offers more!
new Formatter(new StringBuilder()) painlessly appends!
import java.util.Formatter;
import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
public class FormatterTest {
private Formatter formatter;
private StringBuilder sb;
@Before
public void setUp() {
this.formatter = new Formatter(new StringBuilder());
this.sb = new StringBuilder();
}
@Test
public void testArray() {
char[] var= new char[] {‘a’, ‘b’, ‘c’};
sb.append(var+””);
formatter.format(var+””, “”);
assertEquals(sb.toString(), formatter.toString());
}
@Test
public void testInt() {
int var=902;
sb.append(var);
formatter.format(var+””, “”);
assertEquals(sb.toString(), formatter.toString());
}
@Test
public void testFloat() {
float var=902;
sb.append(var);
formatter.format(var+””, “”);
assertEquals(sb.toString(), formatter.toString());
}
}
You can easily read a file in the same dir (esp. in a jar) as your class or anywhere(?) on file system. Methods below are usually conveniently called on the Class object, like
1) simplest usage:
InputStream is = this.getClass().getResourceAsStream(“any file such as a.txt”);
InputStream is = AnyClass.class.getResourceAsStream(“any file such as a.txt”);
InputStream is = GetResourceTest.class.getResourceAsStream(“../../test.txt”);
if (is==null) System.err.println(“file not found”);
Behind the scene, these methods delegate to the classloader’s getResourceAsStream()
http://mindprod.com/jgloss/getresourceasstream.html has good examples.
A host-specific config is saved in a so-called saved-session. To access the list of saved-sessions, go to, paradoxically, _New_Session.._
To see or modify a particular saved-session, you must first Load it. You may need to hit Load several times. Once you are in the “editor” mode on a saved-session,
http://tartarus.org/~simon/putty-snapshots/htmldoc/Chapter4.html#config-saving seems to be a good FAQ for this.
How about the config file for each connection? Apparently putty uses registry…
–DefaultSettings as a template: save it if you repeatedly use this template.
launch -> select DefaultSettings -> LOAD -> change any setting -> come back and (click to) highlight DefaultSettings -> SAVE
–Annotations on http://tldp.org/LDP/abs/html/ioredirintro.html —
bash$ lsof -a -p $$ -d0,1,2
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
bash 363 bozo 0u CHR 136,1 3 /dev/pts/1
bash 363 bozo 1u CHR 136,1 3 /dev/pts/1
bash 363 bozo 2u CHR 136,1 3 /dev/pts/1
bash$ exec 2> /dev/null
bash$ lsof -a -p $$ -d0,1,2
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
bash 371 bozo 0u CHR 136,1 3 /dev/pts/1
bash 371 bozo 1u CHR 136,1 3 /dev/pts/1
bash 371 bozo 2w CHR 1,3 120 /dev/null <—
—http://tldp.org/LDP/abs/html/x17601.html#USINGEXECREF shows —
exec 6>&1 # Link file descriptor #6 with stdout.
# I think this creates a new file descriptor FD#6 as alias of FD#1. FD#6 is probably a **pointer** to the in-memory object FD#1. The object IS the original file descriptor.
exec > $LOGFILE 2>&1 # stdout replaced with file “logfile.txt”.
# the object is not discarded. FD#6 still points to it, but the current process no longer uses that object.
#### this is a useful thing to put into your script, if someone calls your script.
# now the current process will use the original “object” from now on.
exec 1>&6 6>&- # Restore stdout and close file descriptor #6.
XDocument.Parse(_lastResponseNonNull.Content).ToString()
To handle possible exceptions, wrap it in try/catch — http://stackoverflow.com/questions/1123718/format-xml-string-to-print-friendly-xml-string
http://www.ibm.com/developerworks/aix/tutorials/au-unixtips4/section5.html —
To run a group of commands in a subshell, enclose them in parentheses. You can use redirection to send input to the subshell's standard input or to send its *collective* output to a file or a pipeline.
Since the subshell environment is a duplicate of its parent, it inherits all of the variables of the parent. But the parent shell never sees any changes that are made in the subshell environment, and the subshell, in turn, never sees any changes that are made in the parent *after* the subshell is spawned.
To save return code of a command (among many) from a subshell,
echo $? > /tmp/hamper1390848908.$$
# other commands….
) > ${LOG_FILE} 2>&1
read GMI_RET_CODE </tmp/hamper1390848908.$$
Here's a simpler alternative
(
someJavaJob
javaStatus=$?
## any other command
[ $javaStatus -ne 0 ] && exit $javaStatus
) > ${LOG_FILE} 2>&1
subshellStatus=$?
echo $subshellStatus
exit $subshellStatus
-Ddir=/tmp ######## my favorite
Trailing command line args
MY_DIR=/tmp ######## env var in OS
Properties file ##### must include in class path
Spring xml file
windiff supports “moved lines”. when u click on a line in fileA, system jumps to the line in fileB.
Also, the left pane shows slanted lines only for moved lines
– shell: if cmd1; then # evaluates cmd1 as OK if 0, NOK otherwise.
– Perl: if (&sub1(…)) # evalutes sub1 as NOK if 0 or undef or empty list
Perl convention is rooted in perl’s Truth.
Based on [[ teach yourself shell programming ]]
Background — i was looking for a 1)reliable and 2) efficient solution.
type yourCmd > /dev/null 2>&1
echo $? #### should always echo a zero (ok) or non-zero (nok)
type cd > /dev/null 2>&1 && echo ok
type cdddd > /dev/null 2>&1 || echo nok
These were tested personally but some readers (see comment below) reported they don’t always work.
Problem: calendar solution has too many lines of code — clutter
Solution: long dayBefore = date1.getTime() – 24 * 60 * 60 * 1000;
http://www.networkcomputing.com/unixworld/answers/003.html says:
“You are correct that the exit status of a pipeline is reported as the exit status of the last command in the pipeline. What happens to the exit status of the first (or other) command? It is ignored by the shell. However, you should be able to capture it with a little ingenuity.”
Q: how to instantiate a new java Date object with 3 numbers for year, month and date?
I guess Calendar could be one standard solution, but not a one-liner.
Practical solution for the time being: use the deprecated constructors
— new java.util.Date?
Only deprecated constructors do that.
java.sql.Date.valueOf(“2008-04-02” )
–new java.sql.Date?
Only deprecated constructors do that.
java.util.Date.getTime() can feed a long to a java.sql.Date() constructor
I think most if not all shell boolean-constructs evaluate an exit-status. Here are an incomplete list of boolean-constructs — ie constructs about yes/no. Unifying them all, the 2 unifying factors are boolean and exit-status, right?
autosys failure/success? yes
the shell’s IF construct? This is the simplest, base case.
WHILE? same as IF
TEST? same as []
[]? yes. IF [ something ] evaluates the exit status of [ something ]&& , || ? yes
See other post(s) on exit status
http://blogs.sun.com/sundararajan/entry/thou_shall_know_the_class
http://forum.java.sun.com/thread.jspa?threadID=5178593&messageID=9692487 says : Just open the class file with something that can display hexidecimal data and look at bytes 5 – 8 in the file. They contain the minor:major versions in hex.
I used textpad and saw 2E ie 48 for major version. javap reported 0 and 0.
I once had a strange feed file. If I use vi to delete any line, the feed can no longer be processed by the feeder system. I suspect once vi write the file back to disk, it’s corrupted.
Solution: In my case split -1 and head -1 can do a good enough job of deleting lines. Both keep the feed file in good condition.
Q: is vi designed to edit a binary file?
Q: can perl keep all unaffected lines unaffected?
Acid test: less can show the unprintable characters and shows that after deleting one line, every other line has something missing.
find … > /tmp/,341 ; ls -tr `cat /tmp/,341 ` # most powerful
find … -exec ls -l {} \; # space after {}
I think you can also xargs ….
… or make your own xargs with perl -ne “print qx(….)”
ls -S # GNU/FSF version. Unsupported in a few unix flavors.
ls -s | sort # useful even if imperfect
ls -s | sort -n
ls -al | sort -n +4
(Not sure about csh. Let’s focus on /bin/sh and bash for now. I bet everything here also applies to ksh.)
“set” is mostly used to set options. I see it less often used to manipulate variables, which is possible but unnecessarily complicated. In fact
set a=1; echo $a # shows nothing
Are you managing variables in bash? A simple “binary” advice is
– use export for ENV variables
– use “nothing” to manage shell variable — Nothing but “a=1”
How about “let”? Only needed for arithmetic. I would say don’t let this stranger join the club and confuse yourself.
[1] In DOS, “set” command creates variables (http://www.easydos.com/set.html)
based on http://www.xml.com/pub/a/2002/04/17/perl-xml.html.
Find all section titles in a DocBook XML:
# cat files/mybook.xml | xpath //section/title
Retrieve just the significant text (not including nodes containing all-whitespace) from a given document:
# cat files/mybook.xml | xpath “//text()[string-length(normalize-space(.)) > 0 ]”
Save the entire data stored in the ‘users’ table as a huge file users.xml:
# sql2xml.pl -sn myserver -driver Oracle -uid user -pwd seekrit -table user -output users.xml
Pretty-print a bad xml file:
# cat overwrought.xml | xmlpretty > new.xml
Use the built-in HTML parser to convert ill-formed HTML to XML before further processing:
# xmllint –html khampton_perl_xml_17.html | xpath “//a[@href]”
AND MORE….
if [[[ some condition ]]]
elif [[[ some condition ]]]
while [[[ some condition ]]]
2 types of things can replace [[[ some condition ]]]
A) a boolean test like ” [ -r /tmp ] ”
B) any other command, since every command returns an exit status
The common characteristic? Both A and B provide an exit-status to the if/elif/while
Q: what if you have an alias, a shell func, a shell built-in (like “echo”), a unix executable file, and your own script all sharing the same name?
Focus on 2 simple rules for now:
1) Your own aliases override everything else (such as shell functions)
2) $PATH is the very last (after things like shell built-in commands) place searched by the shell. Executables in $PATH are external to the shell.
I think the same precedence holdes for any shell.
I wanted to compare the old version of myClass.java with a new version but the two files live on 2 drives.
Now I just browse to the first myClass.java, right click to mark it for “compare later”. Then i browse to the 2nd file, and right click to compare them.
Immediately the 2 files are loaded in a GUI side-by-side with differences highlighted in color. You can scroll both panes at the same time.
More visual/convenient than WinDiff or CVS-diff in Netbeans.
* The GUI tool is winMerge (http://prdownloads.sourceforge.net/winmerge/WinMerge-2.6.8-Setup.exe)
* The WinExplorer context-menu plug-in is Diff-ext (http://diff-ext.sourceforge.net/downloads.shtml)
Diff-ext also lets u compare 3 files or directories.
Use insert(). Example —
myStringBuffer.insert (0, “prefix string”); // C# and java are similar. See API links below
This technique is rather important to job interview coding tests. (I encountered this in the ITA 50 billion quiz)
Warning — http://stackoverflow.com/questions/738950/c-sharp-or-java-prepend-strings-with-stringbuilder points out that prepend is often less efficient as append
myBuf.insert(5, …) means “insert after 5“, that is, insert after first 5 characters of myBuf.
myBuf.insert(0, …) means insert after 0 character, which is the geeky way of saying prepend
http://docs.oracle.com/javase/6/docs/api/java/lang/StringBuffer.html
http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/StringBuilder.html — faster but thread unsafe
http://msdn.microsoft.com/en-us/library/7tyt41s0(v=vs.110).aspx
$ time java some_class &
Command will return immediately, but u get the timing statistics along with the [Done] message.
start putty -v -load “nbc210.193” -l … -pw
: “start”? close dos window asap
: “load”? to load proxy saved in the session
full-screen may hide the mouse, the start menu …
Solution: alt-tab. Then right click on the tast-bar icon for the offending cmd window
q: threshold?
A: The “threshold” attribute takes a level value such that all
logging statements with a level equal or below this value are
disabled.
Q: root?
A: root of the xml tree is CATEGORY, which typicall references
1 or more appenders, 2nd level node in the xml tree.
Q: eg@appenders?
A: console, snmp, syslog,
q: log4j.xml changes need restart?
A: no
Q: category vs logger?
A: say “category” in xml; say “logger” in src code
#1 tip: child logger inherits from parent logger
Q: Category names are FQCN?
A: yes. “Engine” shown in console but “com.domain.Engine” shown in log file.
simple case study:
u put log4j.jar into tomcat’s ROOT\WEB-INF\lib, u will get this error.
Looks like when system loads this jar it may complain because no log4j config file is present.
