Not all grep implementations provide an “-o” option

2 pointsby textmodeover 3 years ago

For example, Plan9 grep.<p>Solution:<p><pre><code> #!/bin/sh # usage: $0 pattern < file x=$(echo x|tr x '\34'); tr -d '\12'|sed "s/$x//g;s/$1/$x&$x/g"|tr $x '\12'|sed -n "/^$1/p"</code></pre>

1 comment

zinekellerover 3 years ago

It's not mandated by POSIX: <a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html" rel="nofollow">https://pubs.opengroup.org/onlinepubs/9699919799/utilities/g...</a>