Created
May 31, 2022 00:29
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BASH_REMATCH stack: a secret bash feature :O
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| #!/bin/bash -- | |
| # https://lists.gnu.org/archive/html/bug-bash/2022-05/msg00052.html | |
| bashrematch_push () { | |
| local BASH_REMATCH a | |
| for a | |
| do [[ $a =~ .* ]] | |
| done | |
| } | |
| bashrematch_pop () { | |
| local i | |
| for (( i = (${1-1}); i; --i )); do | |
| printf '%s\n' "$BASH_REMATCH" | |
| unset -v BASH_REMATCH | |
| done | |
| } | |
| # Examples: | |
| # bash-5.1$ printf '%s\n' a b c | bashrematch_tac | |
| # c | |
| # b | |
| # a | |
| # | |
| # bash-5.1$ printf 'd\ne\nf\ng' | bashrematch_tac | |
| # gf | |
| # e | |
| # d | |
| bashrematch_tac () { | |
| local REPLY i=0 | |
| while read -r; do | |
| bashrematch_push "$REPLY" | |
| (( ++i )) | |
| done | |
| printf '%s' "$REPLY" | |
| bashrematch_pop "$i" | |
| } | |
| # Examples: | |
| # bash-5.1$ a=( el1 el2 el3 ); bashrematch_reverse "${a[@]}" | |
| # el3 | |
| # el2 | |
| # el1 | |
| bashrematch_reverse () { | |
| bashrematch_push "$@" | |
| bashrematch_pop "$#" | |
| } |
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