Unix
Files and Directories
ls# lists documents in current directorycp <x> <y># copyto mv <x> <y># moveto rm <x># remove filemkdir <x># makes new directorypwd# shows current directorycd <x># goes into folderln -s <x> <y># makes a soft link between real fileand pointer cat <file># list the whole filemore <file># typesin chunks, goes to next chunk less <file># similar to morehead -N <file># types the first N lines (flag-free default is 10?)tail -N <file># types the last N lines (flag-free default is 10?)
Globbing
* # wildcard (any number of chars)
? # wildcard (one car)
vim file.{h,cpp} # open file.h, file.cpp with vim (contrast w/ vim file.*)
In-line scripting
for file in `ls`; do md5sum $file; done # call md5sum on * in the dir
Math
bc # Calculator program
$ echo "obase=16; 15" | bc
F
$ echo "obase=2; 15" | bc
1111
$ echo "scale=3; 1/5" | bc
.200
Quoting
Single quotes treat their contents literally, double quotes allow the shell to evaluate shell constructs.
Escaping & Special Characters
echo a* # wildcard
echo a\* # literal asterisk
echo 'I live in $HOME'
echo "I live in $HOME"
echo "I live in \$HOME"
echo "There is a tab between here^V^I and here." # Use ^V to access the tab (^I)
Editing
set -o vi # Use vim keystrokes to edit the command line (use <esc> to
# enter Normal Mode, <i> to return to Insert Mode).
set -o emacs # Use emacs keystrokes to edit the command line
Fix Windows-style newline characters (translate to Unix-style)
tr '\r' '\n' < file.txt > file.txt
Redirection
some command < infile
some command > outfile # create / overwrite
some command >& outfile # errors from command go to file
some command >> outfile # Append
some command >>& outfile # appends error of command onto end of file
some command 2> errorfile # Create / overwrite
come command > outfile 2> errorfile # output and error stream in separate files
Combining Commands
com1 ; com2 ; com3
com1 && com2 && com3 # stop if any in the sequence fails
com1 || com2 || com3 # stop as soon as any one succeeds
Process Management
CTL-Z # pause the current process and return to console
bg # allow the process you just paused to run in background
fg # move a background process to the foreground
jobs # shows what you're running
ps # shows processes
Help
man <c> # help on command <c>
<c> -h # sometimes has help this way as well
<c> --help # sometimes has help this way as well, verbose flag style
Special Startup/Config Files
.login or .profile # runs on login
.shrc or .cshrc # runs when you invoke a script
Editing and Strings
sed s/<a>/<b>/ <file> >
grep <a> <b> # print out all lines in <b> which contain string <a>
sort <a> # sort the file a
diff <a> <b> # print out the difference between <a> and <b>
xemacs <a> # edit the file <a>
Finding
find . # Recursive listing
find . -name CVS -type d -exec rm -rf {} \; # Find & remove all dirs named CVS; start "here."
find . -name *.o -type f -exec echo {} \; # List all files named *.o; start "here."
find . -name ._* -type f -exec echo {} \; # List all files named ._*; start "here."
find . -name ._* -type f -exec rm {} \; # Find & list all files named ._*; start "here."
mdfind # Mac OSX only - use Spotlight registry for speed.
locate <file> # w/o globbing, treated as "*foo*" (faster, but
# possibly out of date).
Finding and removing recipe
cd /mydirectory
touch -t 1406181700 compare # choose an appropriate reference time
find . -not -newer compare -name "*.*" -exec rm {} \;
rm compare
Searching
grep -n {pattern} * # Search all local files for {pattern} & print line numbers.
grep -i {pattern} * # Perform a case insensitive search.
Files
~> cat > myfile.txt
Line 1
Line 2
<ctrl-d>
~> cat >> my file.txt
<to append to the end>
Look at Files
head -n 1 *.py # Look at the first line of all .py scripts here.
tail -n 20 myfile.txt # Look at the last 20 lines of my file.txt.
watch -n 1 "tail -n 10 job.log" # Every second, look at the last 10 lines of job.log.
Killing Programs
^c # <ctrl>-c; Cancel; only works within shells
kill PID # kill process ID.
^j # Get a shell prompt in a frozen window.
reset ^j # Reset to reset state (may also need ^j)
Terminating a Shell
^d
exit
Environmentals
This depends on what shell you are using. In the bash shells scripts use:
export <X>=<y> # will make $X refer to <y>
export PATH=<y>:${PATH} # will append <y> to $PATH
In the c-shells csh and tcsh:
setenv <x> <y> # is the same thing as export <x>=<y>
env # will list all environmentals you have set
echo $ENV # will print the value of $ENV to the terminal
Important Environmentals:
$HOST
$USER
$HOME # your home area
$PWD # the current directory
$PATH # where unix looks for code to execute
$PYTHONPATH # where unix looks for python modules to import
$LD_LIBRARY_PATH # where unix looks for shared libraries
You normally want to append to the PATHs. Just setting them to
echo $LD_LIBRARY_PATH | tr \: \\n # Show the $PATH nicely, one per line
echo ${USER:0:1} # print the first char of user
echo ${USER:0:2} # print the first two chars of user
echo ${USER#?} # print all but the first char of user
Aliases
Edit .bashrc / .bash_profile : alias minerva01="ssh perdue@minerva01.fnal.gov"
Check with, e.g.: $ type minerva01
Miscellaneous Useful
man ascii # Print a table of all the ascii codes
cal # Bring up a calendar
xxd somefile.bin # Examine hex dump of a binary file (somefile.bin)
od -x somefile.txt # Examine hex dump of a file (can also do octal, decimal, ASCII)
lsb_release -a # Details about "linux release base"
Look at Compiled Binary
strings -a a.out | grep -i gcc # see what compiler was used
——– top memory plot ———
Here are instructions (that Trung gave me) to create the plots:
While running the program also run: top -b -d 1 -u tice » log.txt
When the program is done trim out the lines relevant to your executable: grep -e
If you have two log.dat files, you can plot them together gnuplot> plot “log_1.dat” title “This is title 1”, \