[feature request] --logdir should support globs

This will he helpful for the user to compare several runs instead of all.

tensorboard --logdir setting1-*
tensorboard --logdir setting2-*
tensorboard --logdir *-xxx

[Victarry]

Will this function come in 2021?

[wchargin]

@cytsai: You can do that more easily and safely with a shell alias as well (please do not use os.system like that!), but it only expands the globs at invocation time, not continuously as more files are added that match the glob.

Here is a safe way to achieve the same thing in any POSIX shell:

# usage: multitb GLOB
# runs TensorBoard with a comma-separated list of all logdirs that match
# the glob (at invocation time)
multitb() {
    logdir=
    if [ $# -eq 0 ]; then
        printf >&2 'fatal: provide at least one logdir\n'
    fi
    for arg; do
        logdir="${logdir}${logdir:+,}${arg}"
    done
    (set -x; tensorboard --logdir "${logdir}")
}