Andrew McDonough

Please note: This page is imported from my wiki, which hasn't been updated in over 10 years. Some of the formatting was lost during the import. I'll try to get around to fixing it someday.





Assignment X=“hello” note that there should be no space on either side of the equals sign Referring to echo $X


if [ condition ] then statements else more statements fi


^ Operator ^ Meaning ^ | -eq | Integer equality | | -neq | Integer inequality | | -lt | Integer less than | | -le | Integer less than or equal to | | -gt | Integer greater than | | -ge | Integer greater than or equal to | | = | String equality | | != | String Inequality | | -n | Non empty string | | -z | Empty string | | -d | Directory existence test | | -f | File existence test |


Iterate over files and print their names: for i in $(ls); do echo $i; done

Iterate over .zip files and extract them for i in $(ls *.zip); do unzip $i; done


Accepting input The following bash script accepts a parameter or prompts for the value if it is not supplied. For the sake of the example, it simply echos this to STDOUT


MYVAR="" if [ -z $1 ] then echo Enter a value: read MYVAR else MYVAR=$1 fi echo $MYVAR

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Andrew McDonough

Andrew McDonough is a consultant CTO and software developer, currently based between Berlin and London.

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