zsh/rc: Create program functions only if the programs are installed.

diff --git a/zsh/rc b/zsh/rc
index ca125967f14840a584ef057b9de0ad8c87d8a0d5..e34d9050232303a781951abe0559b2c63740d9cd 100644 (file)
--- a/zsh/rc
+++ b/zsh/rc
@@ -655,17 +655,17 @@ fi
 # Display all branches (except stash) in gitk but only 200 commits as this is
 # much faster. Also put in the background and disown. Thanks to drizzd in #git
 # on Freenode (2010-04-03 17:55 CEST).
-gitk() {
+(( $+commands[gitk] )) && gitk() {
     command gitk --max-count=200 --branches --remotes --tags "$@" &
     disown %command
 }
 # Same for tig (except the disown part as it's no GUI program).
-tig() {
+(( $+commands[tig] )) && tig() {
     command tig --max-count=200 --branches --remotes --tags "$@"
 }
 
 # Pipe output through less.
-tree() {
+(( $+commands[tree] )) && tree() {
     command tree -C "$@" | less
 }