* [email protected] <[email protected]> [25-05/15=Th 08:42 -0700]: >> ev () { case $# in >> 0) /usr/bin/evince --display=:0 ;; >> 1) /usr/bin/evince --display=:0 $1 ;; >> *) echo "Too many arguments." ;; esac } >> Can improvements be suggested?
* ? <[email protected]> [25-05/15=Th 18:23 +0200]: > you can shorten ev to > ev(){ evince -d ${DISPLAY=:0} ${1+"$@"};} That makes $DISPLAY equal ":0", which Peter's version didn't do. If he were always running evince on a local display and had only one, that could be a convenience, except that if he's usually running it as ev(), then it's just a potential confusion for when he (or some other function or script) spells out the command. And if he only has one display, he can just default to :0. > you might wanna background it from your tty > ev() { evince ${1+"$@"}&} Your versions and Peter's all discard any args beyond $1, but evince can display multiple URLs (which `man evince` initially refers to as "filename(s)", clarifying only farther down the man page). Special-casing zero args with the case statement is unnecessary: -------------------------------- popos/pts/5 bash ~ 09:47 0$set -- a b c # define 3 args popos/pts/5 bash ~ 09:47 0$echo $# # count them 3 popos/pts/5 bash ~ 09:47 0$set -- # define 0 args popos/pts/5 bash ~ 09:48 0$echo $# # observe count of 0 0 popos/pts/5 bash ~ 09:48 0$set -- "$@" # define as many args as "$@" is popos/pts/5 bash ~ 09:48 0$echo $# # still 0 0 popos/pts/5 bash ~ 09:49 0$set -- "" # define as many args as "" is popos/pts/5 bash ~ 09:49 0$echo $# # Aha, *that's* an arg! 1 popos/pts/5 bash ~ 09:49 0$ -------------------------------- In other words, "" is one arg which is the empty string, but "$@" is exactly the number of args that have been defined, possibly zero. Still, Peter's ev() isn't equivalent to ev(){ evince "$@";} because Peter's forces the display to be ":0"; so ev(){ evince -d:0 "$@";} and ev(){ evince --display=:0 "$@";} are closer to Peter's except that they allow multiple URLs. Even closer to Peter's (differing only in sending the error message to standard error instead of standard output) is ev(){ (($# == 1)) && evince -d:0 "$@" || echo >&2 "Too many args";} but I can't think of a reason to want to do that.
