Linux command line best practices and tips

Use the -f flag to print the canonicalized version. For example:

readlink -f /root/Public/myothertextfile.txt

From man readlink:

-f, --canonicalize
      canonicalize by following every symlink in every component of the given name recursively; all but the last component must exist

The shell/OS imposed limit is usually one or two hundred thousand characters.

getconf ARG_MAX will give you the maximum input limit for a command. On the Debian system I currently have a terminal open on this returns 131072 which is 128*1024. The limit is reduced by your environment variables and if my memory serves me correctly these are passed in the same structure by the shell, though that will only take off a few hundred characters in most cases. To find an approximation of this value run env | wc -c - this suggests 325 characters at the current time on this login on this machine.

Scripts are likely to permit this full length, but it is not unlikely that other utilities will impose their own limits either intentionally or through design issues. There may also be artificial limits to how long an individual argument on a long command line can be, and/or how long a path to a file can be.