How do you normalize a file path in Bash?
if you're wanting to chomp part of a filename from the path, "dirname" and "basename" are your friends, and "realpath" is handy too.
dirname /foo/bar/baz
# /foo/bar
basename /foo/bar/baz
# baz
dirname $( dirname /foo/bar/baz )
# /foo
realpath ../foo
# ../foo: No such file or directory
realpath /tmp/../tmp/../tmp
# /tmp
realpath
alternatives
If realpath
is not supported by your shell, you can try
readlink -f /path/here/..
Also
readlink -m /path/there/../../
Works the same as
realpath -s /path/here/../../
in that the path doesn't need to exist to be normalized.
I don't know if there is a direct bash command to do this, but I usually do
normalDir="`cd "${dirToNormalize}";pwd`"
echo "${normalDir}"
and it works well.
Try realpath
. Below is the source in its entirety, hereby donated to the public domain.
// realpath.c: display the absolute path to a file or directory.
// Adam Liss, August, 2007
// This program is provided "as-is" to the public domain, without express or
// implied warranty, for any non-profit use, provided this notice is maintained.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>
#include <limits.h>
static char *s_pMyName;
void usage(void);
int main(int argc, char *argv[])
{
char
sPath[PATH_MAX];
s_pMyName = strdup(basename(argv[0]));
if (argc < 2)
usage();
printf("%s\n", realpath(argv[1], sPath));
return 0;
}
void usage(void)
{
fprintf(stderr, "usage: %s PATH\n", s_pMyName);
exit(1);
}
A portable and reliable solution is to use python, which is preinstalled pretty much everywhere (including Darwin). You have two options:
-
abspath
returns an absolute path but does not resolve symlinks:python -c "import os,sys; print(os.path.abspath(sys.argv[1]))" path/to/file
-
realpath
returns an absolute path and in doing so resolves symlinks, generating a canonical path:python -c "import os,sys; print(os.path.realpath(sys.argv[1]))" path/to/file
In each case, path/to/file
can be either a relative or absolute path.