18.5.1 Realpath usage examples

By default, realpath prints the absolute file name of given files (symlinks are resolved, words is resolved to american-english):

cd /home/user
realpath /usr/bin/sort /tmp/foo /usr/share/dict/words 1.txt
⇒ /usr/bin/sort
⇒ /tmp/foo
⇒ /usr/share/dict/american-english
⇒ /home/user/1.txt

With --relative-to, file names are printed relative to the given directory:

realpath --relative-to=/usr/bin \
         /usr/bin/sort /tmp/foo /usr/share/dict/words 1.txt
⇒ sort
⇒ ../../tmp/foo
⇒ ../share/dict/american-english
⇒ ../../home/user/1.txt

With --relative-base, relative file names are printed if the resolved file name is below the given base directory. For files outside the base directory absolute file names are printed:

realpath --relative-base=/usr \
         /usr/bin/sort /tmp/foo /usr/share/dict/words 1.txt
⇒ bin/sort
⇒ /tmp/foo
⇒ share/dict/american-english
⇒ /home/user/1.txt

When both --relative-to=DIR1 and --relative-base=DIR2 are used, file names are printed relative to dir1 if they are located below dir2. If the files are not below dir2, they are printed as absolute file names:

realpath --relative-to=/usr/bin --relative-base=/usr \
         /usr/bin/sort /tmp/foo /usr/share/dict/words 1.txt
⇒ sort
⇒ /tmp/foo
⇒ ../share/dict/american-english
⇒ /home/user/1.txt

When both --relative-to=DIR1 and --relative-base=DIR2 are used, dir1 must be a subdirectory of dir2. Otherwise, realpath prints absolutes file names.