Shell Programming and Scripting

(no, i can't switch shells, although i'd love to. yes, i have read http://www.grymoire.com/Unix/CshTop10.txt.)

i finally managed to get an alias working the way i want it to, but i don't understand how one part of it works (highlighted in red):

Code:

alias log ' \\
    set x=`echo \!:1 | /bin/sed -e "s/\([^_]\)/\1*\{_,\}/g" -e "s|\(.*\)|$L/\1*|"`; \\
    80; ls -1hAFL $x; 80; set x=`echo $x | /bin/awk '\''{ print $1 }'\''`; \!:2* $x;'

i've done plenty of googling, but i don't get it. what does the escaped single-quote even mean? is the outer-most single-quote (the entire alias expression) closed by the first red single-quote, or is the first red single-quote the start of another set of weirder quotes, or...

It's there to protect the `command` subexpression from being evaluated at the time the alias is created. You want this command to actually run when the alias is executed. The { print $1 } is a tiny awk script which must be quoted to prevent $1 from being evaluated by the shell at run-time.

By the way, you could avoid these funny quotes by using cut:

Code:

set x=`echo $x|cut -d " " -f 1`