On Sun, Jan 12, 2025 at 8:24 AM Félix Hauri <fe...@f-hauri.ch> wrote:
> Le Sat, Jan 11, 2025 at 10:49:50AM -0500, Greg Wooledge a écrit : > > https://mywiki.wooledge.org/BashPitfalls#pf47 > > "It's a feature." > > > -- how do we work around this nonsense? > > I've alredy noticed this, but never stictly tested them as: > > for row in k{:v1{:v2{:{:{:,},},},:{:{:,},},},:{:{:,},},}; do > IFS=: read k v <<<"$row"; > printf "%-20s %s\n" "row='$row'" "k='$k', v='$v'"; > done > row='k:v1:v2:::' k='k', v='v1:v2:::' > row='k:v1:v2::' k='k', v='v1:v2::' > row='k:v1:v2:' k='k', v='v1:v2:' > row='k:v1:v2' k='k', v='v1:v2' > row='k:v1:::' k='k', v='v1:::' > row='k:v1::' k='k', v='v1::' > row='k:v1:' k='k', v='v1' > row='k:v1' k='k', v='v1' > row='k:::' k='k', v='::' > row='k::' k='k', v='' > row='k:' k='k', v='' > row='k' k='k', v='' > > Thanks for driving my attention to this *feature*! > > -- > Félix Hauri - <fe...@f-hauri.ch> - http://www.f-hauri.ch > > Greg's link provides a workaround: $ input='foo:bar:' $ echo "$input:" | { IFS=: read -r f1 rest; rest=${rest%:}; declare -p rest; } declare -- rest="bar:" However it only works for reading a single line. If you want to read a file, I think `sed` might be worthwhile instead of doing this individually for every line in a loop. Here is a `sed` version: delim=, { sed -r -e "s/\$/$delim/" | while IFS="$delim" read -r k values; do values="${values%$delim}" echo "k='$k' v='$values'" done } <<EOT a,b,c,d,e a,b,c,d, a,b,c,d a,b,c, a,b,c a,b, a,b a, a EOT And here is a version you would have to use without `sed` to get the line first, before you can append the field terminator to it: delim=, { while IFS= read -r row; do IFS="$delim" read -r k values < <(echo "$row$delim") values="${values%$delim}" printf "%-20s %s\n" "row='$row'" "k='$k' v='$values'" done } <<EOT a,b,c,d,e a,b,c,d, a,b,c,d a,b,c, a,b,c a,b, a,b a, a EOT
