Extract file basename without path and extension in bash

Given file names like these:

/the/path/foo.txt
bar.txt

I hope to get:

foo
bar

Why this doesn't work?

#!/bin/bash

fullfile=$1
fname=$(basename $fullfile)
fbname=${fname%.*}
echo $fbname

What's the right way to do it?

You don't have to call the external basename command. Instead, you could use the following commands:

$ s=/the/path/foo.txt
$ echo "${s##*/}"
foo.txt
$ s=${s##*/}
$ echo "${s%.txt}"
foo
$ echo "${s%.*}"
foo

Note that this solution should work in all recent (post 2004) POSIX compliant shells, (e.g. bash, dash, ksh, etc.).

Source: Shell Command Language 2.6.2 Parameter Expansion

More on bash String Manipulations: http://tldp.org/LDP/LG/issue18/bash.html

The http://opengroup.org/onlinepubs/007908799/xcu/basename.html">basename</a> command has two different invocations; in one, you specify just the path, in which case it gives you the last component, while in the other you also give a suffix that it will remove. So, you can simplify your example code by using the second invocation of basename. Also, be careful to correctly quote things:

fbname=$(basename "$1" .txt)
echo "$fbname"

A combination of basename and cut works fine, even in case of double ending like .tar.gz:

fbname=$(basename "$fullfile" | cut -d. -f1)

Would be interesting if this solution needs less arithmetic power than Bash Parameter Expansion.

Here are oneliners:

1. $(basename "${s%.*}")
2. $(basename "${s}" ".${s##*.}")

I needed this, the same as asked by bongbang and w4etwetewtwet.

Pure bash, no basename, no variable juggling. Set a string and echo:

p=/the/path/foo.txt
echo "${p//+(*\/|.*)}"

Output:

foo

Note: the bash extglob option must be "on", (Ubuntu sets extglob "on" by default), if it's not, do:

shopt -s extglob

---

Walking through the ${p//+(*\/|.*)}:

1. ${p -- start with $p.
2. // substitute every instance of the pattern that follows.
3. +( match one or more of the pattern list in parenthesis, (i.e. until item #7 below).
4. 1st pattern: *\/ matches anything before a literal "/" char.
5. pattern separator | which in this instance acts like a logical OR.
6. 2nd pattern: .* matches anything after a literal "." -- that is, in bash the "." is just a period char, and not a regex dot.
7. ) end pattern list.
8. } end parameter expansion. With a string substitution, there's usually another / there, followed by a replacement string. But since there's no / there, the matched patterns are substituted with nothing; this deletes the matches.

Relevant man bash background:

1. pattern substitution:

> ${parameter/pattern/string} > Pattern substitution. The pattern is expanded to produce a pat > tern just as in pathname expansion. Parameter is expanded and > the longest match of pattern against its value is replaced with > string. If pattern begins with /, all matches of pattern are > replaced with string. Normally only the first match is > replaced. If pattern begins with #, it must match at the begin‐ > ning of the expanded value of parameter. If pattern begins with > %, it must match at the end of the expanded value of parameter. > If string is null, matches of pattern are deleted and the / fol > lowing pattern may be omitted. If parameter is @ or *, the sub > stitution operation is applied to each positional parameter in > turn, and the expansion is the resultant list. If parameter is > an array variable subscripted with @ or *, the substitution > operation is applied to each member of the array in turn, and > the expansion is the resultant list.

2. extended pattern matching:

> If the extglob shell option is enabled using the shopt builtin, several > extended pattern matching operators are recognized. In the following > description, a pattern-list is a list of one or more patterns separated > by a |. Composite patterns may be formed using one or more of the fol > lowing sub-patterns: > > ?(pattern-list) > Matches zero or one occurrence of the given patterns > *(pattern-list) > Matches zero or more occurrences of the given patterns > +(pattern-list) > Matches one or more occurrences of the given patterns > @(pattern-list) > Matches one of the given patterns > !(pattern-list) > Matches anything except one of the given patterns

Here is another (more complex) way of getting either the filename or extension, first use the rev command to invert the file path, cut from the first . and then invert the file path again, like this:

filename=`rev <<< "$1" | cut -d"." -f2- | rev`
fileext=`rev <<< "$1" | cut -d"." -f1 | rev`

If you want to play nice with Windows file paths (under Cygwin) you can also try this:

fname=${fullfile##*[/|\\]}

This will account for backslash separators when using BaSH on Windows.

Just an alternative that I came up with to extract an extension, using the posts in this thread with my own small knowledge base that was more familiar to me.

ext="$(rev <<< "$(cut -f "1" -d "." <<< "$(rev <<< "file.docx")")")"

Note: Please advise on my use of quotes; it worked for me but I might be missing something on their proper use (I probably use too many).

Use the basename command. Its manpage is here: http://unixhelp.ed.ac.uk/CGI/man-cgi?basename