Dirname

  is a standard computer program on Unix and Unix-like operating systems. When  is given a pathname, it will delete any suffix beginning with the last slash  character and return the result. is described in the Single UNIX Specification and is primarily used in shell scripts.

History
The version of  bundled in GNU coreutils was written by David MacKenzie and Jim Meyering. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The dirname command has also been ported to the IBM i operating system.

Usage
The Single UNIX Specification for  is: dirname string


 * A pathname
 * A pathname

$ dirname /home/martin/docs/base.wiki /home/martin/docs

$ dirname /home/martin/docs/. /home/martin/docs $ dirname /home/martin/docs/ /home/martin $ dirname base.wiki . $ dirname / /

Performance
Since  accepts only one operand, its usage within the inner loop of shell scripts can be detrimental to performance. Consider The above excerpt would cause a separate process invocation for each line of input. For this reason, shell substitution is typically used instead or if relative pathnames need to be handled as well Note that these handle trailing slashes differently than dirname.

Misconceptions
We might think that paths that end in a trailing slash are a directory. But actually, the trailing slash represents all files within the directory.

/home/martin/docs/.