Bash Array Cheatsheet

gistfile1.txt

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║ Syntax          ║ Result                                 ║
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║ arr=()          ║ Create empty array                     ║
║ arr=(1 2 3)     ║ Initialize array                       ║
║ ${arr[2]}       ║ Retrieve third element                 ║
║ ${arr[@]}       ║ Retrieve all elements                  ║
║ ${!arr[@]}      ║ Retrieve array indices                 ║
║ ${#arr[@]}      ║ Calculate array size                   ║
║ arr[0]=3        ║ Overwrite 1st element                  ║
║ arr+=(4)        ║ Append value(s)                        ║
║ str=$(ls)       ║ Save ls output as string               ║
║ arr=( $(ls) )   ║ Save ls output as array of files       ║
║ ${arr[@]:s:n}   ║ Elements at indices n to s+n           ║
║ ${str//ab/c}    ║ For a given string, replace ab with c  ║
║ ${arr[@]//ab/c} ║ For each array item, replace ab with c ║
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