Comment on When to use "cat -n" instead of "wc -l"Comments−susam8moI have always used 'nl' for numbering lines. That's how I learnt it from a Unix book around 2000 and the habit has stuck with me. And it's specified in POSIX: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/n...In fact, I wasn't aware of the 'cat -n' option until now. It appears to be supported by both BSD cat and GNU cat, although not specified in POSIX: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/c...Both examples in the post produce identical output when run through 'nl'. Here are a few commands to confirm this: diff <(seq 3 14 | cat -n) <(seq 3 14 | nl) diff <(look . | grep '^.b..t$' | cat -n) <(look . | grep '^.b..t$' | nl) Aside: Since I'm talking about POSIX here, it's worth mentioning that process substitution using '<(commands)' is not specified in POSIX, but it's supported in bash, zsh, ksh93, etc.
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I have always used 'nl' for numbering lines. That's how I learnt it from a Unix book around 2000 and the habit has stuck with me. And it's specified in POSIX: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/n...
In fact, I wasn't aware of the 'cat -n' option until now. It appears to be supported by both BSD cat and GNU cat, although not specified in POSIX: https://pubs.opengroup.org/onlinepubs/9799919799/utilities/c...
Both examples in the post produce identical output when run through 'nl'. Here are a few commands to confirm this:
Aside: Since I'm talking about POSIX here, it's worth mentioning that process substitution using '<(commands)' is not specified in POSIX, but it's supported in bash, zsh, ksh93, etc.