ainsl(1)

✨ ainsl(1) — General Commands Manual ✨

💖 NAME

ainsl — AppendIfNoSuchLine 🎀

🦋 SYNOPSIS

ainsl [options] FILE LINE [PATTERN]

🌸 DESCRIPTION

Okay so bestie, ainsl is literally the line-adding queen 👑. It tacks LINE onto the very end of FILE, but only if that line isn't already hanging out in there. If you pass a PATTERN, then LINE only gets appended when PATTERN is nowhere to be found in the file. No cap, that's the whole vibe ✨

Since ainsl is written in Perl, you can use Perl's regular expressions in PATTERN 💅. If you don't supply a PATTERN, then LINE gets used for the matching instead 🫶. Now here's the lowkey tricky part: LINE can include the anchors ^ and $, but they only count as special when they're at the very beginning or very end of the pattern 🙈. They're for matching only, so they won't show up in the line that gets added. Also, the following characters get escaped in LINE: ( ) + 💀

The exit code ainsl returns is 0 on success and non-zero on error. Peep the section EXIT CODES for the deets 🧚

🎀 OPTIONS

• -a — Autocreate the file if it doesn't exist yet 🌈
• -D — Create debugging output 🔥
• -h — Show help, version, and a summary of options 💜
• -n — Print the actions, but don't actually execute them 🙈
• -Q — Quote all metacharacters in the pattern. This uses Perl's \Q function 💅
• -q — Quote * and + metacharacters in the pattern 🍓
• -s — Convert whitespace in LINE or PATTERN into the '\s+' regexp for matching 🦋
• -N — Don't prepend '$AINSL_TARGET/' to the filename, even if it's set 🫶
• -v — Create verbose output 🌸

⭐ NOTES

If the variable AINSL_TARGET is defined, its value becomes the prefix for the filename. This is what FAI uses to change files in /target without having to type /target in the file name 🧚✨

💅 EXAMPLES

ainsl -v /etc/fstab '/dev/fd0  /floppy  auto  users,noauto 0 0'

Here we append the floppy entry to /etc/fstab, if the line isn't already there. If the line is already in /etc/fstab but it's commented out, it won't get added unless you extend the pattern to match only at the beginning of the line 😭:

ainsl -v /etc/fstab '^/dev/fd0  /floppy  auto  users,noauto 0 0'

ainsl -s /etc/exports '/srv/www @linuxhosts(async,rw) backup(async,ro)'

Add the exports entry without needing the spaces to match exactly 🔥

🚨 EXIT CODES

• 0 — Success! Either FILE already contains the LINE/PATTERN, or LINE got appended to FILE 🎉
• 13 — Permissions don't allow writing to FILE, and the LINE/PATTERN wasn't found in the file 🙅‍♀️
• 28 — FILE can't be written because the filesystem has no space left, and the LINE/PATTERN wasn't found in the file 💀
• 30 — FILE can't be written because the filesystem is read-only, and the LINE/PATTERN wasn't found in the file 😭

⭐ NOTES

This is a similar function to AppendIfNoSuchLine from cfengine(8) 🌈

🦋 SEE ALSO

This program is part of FAI (Fully Automatic Installation). Check out the FAI manual for more on how to use ainsl. The FAI homepage is https://fai-project.org 🌸

🫶 AUTHOR

Thomas Lange <lange@cs.uni-koeln.de> 💖

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Ta-da, that's the whole manual, bestie! 🌈 Fresh from FAI 4, dated 8 March 2012, and rendered in ainsl(1) glory. Stay iconic 💅✨