Re: Adding option to select file types

[Stefan Krusche]

Am Mittwoch, 7. Juli 2021 schrieb lisa-asket@perso.be:
> print-region ()
> {
> if (($# < 3)); then
> echo "usage: print-region startline endline startdir [extension ...]"
> >&2 echo "If extensions are not provided, .org and .texi will be
> used." >&2 return 1
> fi
>
> local na=$1
> local nb=$2
> local dir=$3
> shift 3
>
> if (($# == 0)); then
> set -- .org .texi
> fi
>
> # Construct find arguments dynamically from the extension list.
> local findargs=( "$dir" '(' )
> local ext
> for ext in "$@"; do
> findargs+=( -name "*$ext" -o )
> done
> # Overwrite the final -o with ')'
> findargs[${#findargs[@]}-1]=')'
>
> find "${findargs[@]}" \
>    -exec awk -v a="$na" -v b="$nb" '
>      FNR == 1 {s="\n==> "FILENAME" <==\n"; f = 0}
>      FNR == a {print s; f = 1}
>      f {print; if (FNR == b) nextfile}
> ' {} +
> }
>
> I cannot understand on mhy you use "$dir"

Because of the syntax of command "find" which can be peculiar:

SYNOPSIS
       find [-H] [-L] [-P] [-D debugopts] [-Olevel] [starting-point...]
       [expression]

"$dir" in the above example is the "starting-point" because none of the 
options are applied. It is the root of the path that find shall look in 
and has to be the first argument if you do not use one of the options. 
Everything else is part of "expression" which contains normally the 
tests you do on the files.

HTH

Kind regards, Stefan