Tags: unix, os x, linux, command line, terminal, bash, shell
Date: 2013-08-20 23:09:02
Command line tutorial
To learn more, try the command line basics and UNIX tutorials found at http://www.ee.surrey.ac.uk/Teaching/Unix/ and http://www.westwind.com/reference/OS-X/commandline/navigation.html.
Requirements
Open a command line shell:
- use 'Terminal' on OS X or Linux
- use cygwin on Windows (need to install first)
Examples
List files
ls
Change directory
cd Desktop
Change up one directory level
cd ..
Print current directory location
pwd
Go to root of drive
cd /
Go back to user home folder
cd ~
Read in the Lord Of The Rings (LOTR) calendar with concatenate (should work on most Linux and Mac OS X systems):
cat /usr/share/calendar/calendar.lotr
Read help for cat
man cat
Use b and spacebar to move forward and backwards a page at time when viewing man help pages. Press q to quit.
Find all lines about 'Frodo' by piping the output from 'cat' into the 'grep' find program with the pipe operator |:
cat /usr/share/calendar/calendar.lotr | grep 'Frodo'
Same exact result as giving grep both original inputs:
grep 'Frodo' /usr/share/calendar/calendar.lotr
Find all lines ending with 'Gandalf' using a 'regular expression' search pattern. To do this use the flag -e and the $ in the search pattern to indicate the line ending position:
cat /usr/share/calendar/calendar.lotr | grep -e 'Gandalf$'
Save this output to a file on the Desktop. Notice the usage of both a pipe | and a redirection of output >:
cd ~/Desktop
cat /usr/share/calendar/calendar.lotr | grep -e 'Gandalf$' > testfile.txt
Append something to the file using the redirection with append marker >>:
echo 'Double Rainbow!' >> testfile.txt
Useful examples
Print file usage
List usage in human-readable format for a directory
du -sh *
List file creation timestamps in seconds and filenames from ls command
ls -lT *.tif | sort | awk '{ print $10, $8 }' > frametimes.txt
find . -name '*.tif ' | xargs ls -lT | sort | awk '{ print $10, $8 }' | sed -Ee 's/^.\///g' > ~/Desktop/frametimes.txt
List date times for .tif CCD movies for pasting into a spreadsheet
ls -lTU *.tif | awk '{ print $6, $7, $8, $9}' > ~/Desktop/frametimes.txt #U is file creation date-- file modification time might be better...
ls -lT *.tif | awk '{ print $6, $7, $8, $9}' | pbcopy
ls -lT *.tif | awk '{ print $10}' > ~/Desktop/frametimes.txt
List filenames without pathnames
ls -lT *.tif | awk '{ print $10}' | pbcopy
ls -lTU *.tif | awk '{ print $6, $7, $8, $9 }' > ~/Desktop/movietimes.txt
Print tiff header information
tiffutil -info filename.tif
Copy files only less than 500MB in size
rsync -av --max-size=500M FilePathToSource FilePathToDestination