Let\'s say, you have a Bash alias
like:
alias rxvt=\'urxvt\'
which works fine.
However:
IMHO the real answer is that you can't escape single-quotes within single-quoted strings.
Its impossible.
If we presume we are using bash.
From bash manual...
Enclosing characters in single quotes preserves the literal value of each
character within the quotes. A single quote may not occur
between single quotes, even when preceded by a backslash.
You need to use one of the other string escape mechanisms " or \
There is nothing magic about alias
that demands it use single quotes.
Both the following work in bash.
alias rxvt="urxvt -fg '#111111' -bg '#111111'"
alias rxvt=urxvt\ -fg\ \'#111111\'\ -bg\ \'#111111\'
The latter is using \ to escape the space character.
There is also nothing magic about #111111 that requires single quotes.
The following options achieves the same result the other two options, in that the rxvt alias works as expected.
alias rxvt='urxvt -fg "#111111" -bg "#111111"'
alias rxvt="urxvt -fg \"#111111\" -bg \"#111111\""
You can also escape the troublesome # directly
alias rxvt="urxvt -fg \#111111 -bg \#111111"