Given one argument, reads which branch head the given symbolic ref refers to and outputs its path, relative to the .git/ directory . Typically you would give HEAD as the <name> argument to see which branch your working tree is on . Given two arguments, creates or updates a symbolic ref <name> to point at the given branch <ref> . Given --delete and an additional argument, deletes the given symbolic ref . A symbolic ref is a regular file that stores a string that begins with ref:refs/ . For example, your .git/HEAD is a regular file whose contents is ref:refs/heads/master .
In the past, .git/HEAD was a symbolic link pointing at refs/heads/master . When we wanted to switch to another branch, we did ln-sf refs/heads/newbranch .git/HEAD ,and when we wanted to find out which branch we are on, we did readlink.git/HEAD . But symbolic links are not entirely portable, so they are now deprecated and symbolic refs (as described above) are used by default . gitsymbolic -ref will exit with status 0 if the contents of the symbolic ref were printed correctly, with status 1 if the requested name is not a symbolic ref, or 128 if another error occurs .