Bash functional: Difference between revisions
From wikinotes
(→Map) |
(→Map) |
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</syntaxhighlight> | </syntaxhighlight> | ||
Example | {{ expand | ||
| Example | |||
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<syntaxhighlight lang="bash"> | <syntaxhighlight lang="bash"> | ||
print_if_divisible_by_2() { | print_if_divisible_by_2() { | ||
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#> 4:yes | #> 4:yes | ||
</syntaxhighlight> | </syntaxhighlight> | ||
}} | |||
</blockquote><!-- Map --> | </blockquote><!-- Map --> | ||
Revision as of 19:10, 11 December 2022
Filter
# filters out results not matching 'grep foo' find . \ | while read line; do \ echo $line | grep foo && echo "$line"; \ done
Map
NOTE:
If your callable accepts parameter as stdin, you don't need map (ex. grep/sed work just fine from stdin).
map() { # Call callable/params($*), passing each each STDIN line as the last parameter local input while read -r input; do "$@" "${input}" done }Example
print_if_divisible_by_2() { if [ $(($1 % 2)) -eq 0 ] ; then echo "$1:yes" else echo "$1:no" fi } echo {1..4} | tr ' ' '\n' | map print_if_divisible_by_2 #> 1:no #> 2:yes #> 3:no #> 4:yes