How to Expand Relative Paths in Shell Script

How to retrieve absolute path given relative

use:

find "$(pwd)"/ -type f

to get all files or

echo "$(pwd)/$line"

to display full path (if relative path matters to)

Expanding a relative path to a full path when running a C program in shell

Your question is not very well worded so I am not sure I am answering the same question that you are asking, but you can convert "./myScript" to its full path using the realpath() function.

Reliable way for a Bash script to get the full path to itself

Here's what I've come up with (edit: plus some tweaks provided by sfstewman, levigroker, Kyle Strand, and Rob Kennedy), that seems to mostly fit my "better" criteria:

SCRIPTPATH="$( cd -- "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"

That SCRIPTPATH line seems particularly roundabout, but we need it rather than SCRIPTPATH=`pwd` in order to properly handle spaces and symlinks.

The inclusion of output redirection (>/dev/null 2>&1) handles the rare(?) case where cd might produce output that would interfere with the surrounding $( ... ) capture. (Such as cd being overridden to also ls a directory after switching to it.)

Note also that esoteric situations, such as executing a script that isn't coming from a file in an accessible file system at all (which is perfectly possible), is not catered to there (or in any of the other answers I've seen).

The -- after cd and before "$0" are in case the directory starts with a -.

How to obtain the absolute path of a file via Shell (BASH/ZSH/SH)?

Use realpath

$ realpath example.txt
/home/username/example.txt

How do I convert relative directory names to absolute ones recognized by Bash?

~/tmp actually is an absolute path from the bash point of view. However this relies on bash to substitute the ~ to the user accounts home folder path, so to something like /home/users/someone/tmp which clearly is an absolute path. That is a buildin feature of the bash shell usually called "path expansion". A relative path would be something like ./tmp or just tmp, so something that has to be interpreted relative to the current working directory of the process.

That substitution does not get applied here apparently. You can use a slightly altered command to achieve what you are looking for by explicitly forcing such expansion in a sub shell command:

if [ -d `eval echo $CMDLINE_FILENAME` ]; then echo "Valid directory!"; fi

That one works for absolute and relative paths, but also for entries that rely on the bash path expansion:

bash:~$ read CMDLINE_FILENAME 
~/tmp
bash:~$ echo "$CMDLINE_FILENAME"
~/tmp
bash:~$ if [ -d `eval echo $CMDLINE_FILENAME`]; then echo "Valid directory!"; fi 
Valid directory!

This does carry the risk of miss usage, though: the eval directive is a pretty mighty tool ...

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