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Shell Cheat Sheet

Shell: Basics

pwd print working directory

ls list directory

  • -l: list file information
  • -lh: list human readable file information

cd change directory

Shell: Interacting with Files

mkdir make directory

cat send file or files to output (in most cases, print to shell)

head output first 10 lines of a file or files

tail output last 10 lines of a file or files

mv rename or move a file or files. Syntax for renaming a file: mv FILENAME NEWFILENAME

cp copy a file or files. Syntax: cp FILENAME NEWFILENAME

> redirect output. Syntax with cat: cat FILENAME1 FILENAME2 > NEWFILENAME

rm remove a file or files. NB: USE WITH EXTREME CAUTION!!!

Shell: Wildcards

? a placeholder for one character or number

* a placeholder for zero or more characters or numbers

[] defines a class of characters

Examples

  • foobar?: matches seven character strings starting with foobar and ending with one character or number
  • foobar*: matches strings starting with foobar ending with zero or more further characters or numbers
  • foobar*txt: matches strings starting with foobar and ending with txt
  • [1-9]foobar?: matches eight character strings starting that start with a number, have foobar after the number, and end with any character or number.

Shell: Counting and Mining

wc word count

  • -w: count words
  • -l: count lines
  • -c: count characters

sort sort input

grep global regular expression print

  • -c: displays counts of matches for each file
  • -i: match with case insensitivity
  • -w: match whole words
  • -v: exclude match
  • --file=FILENAME.txt: use the file FILENAME.txt as the source of strings used in query
  • **|**: (vertical bar character) send output from one command into another comma