Save wrong line bash

A simple thing to do when you realize you just typed the wrong line is hit Ctrl+C; if you want to keep the line, but need to execute something else first, begin a new line with a back slash - \, then Ctrl+C. The line will remain in your history.

Latex Dashes

Hyphen: daughter-in-law, X-rated\\
En dash: pages 13--67\\
Em dash: yes---or no? \\
Minus sign: $0$, $1$ and $-1$

Bash trim filename

However, buried in there is a section on Parameter Substitution which tells us that $foo is really a shorthand for ${foo} which is really the simplest case of several ${foo:operators} and similar constructs.

Given:
foo=/tmp/my.dir/filename.tar.gz

We can use these expressions:

path = ${foo%/*}

To get: /tmp/my.dir (like dirname)

file = ${foo##*/}

To get: filename.tar.gz (like basename)

base = ${file%%.*}

To get: filename

ext = ${file#*.}

To get: tar.gz



${variable%pattern}
Trim the shortest match from the end
${variable##pattern}
Trim the longest match from the beginning
${variable%%pattern}
Trim the longest match from the end
${variable#pattern}
Trim the shortest match from the beginning