- set v [list $::_git $name]
- } elseif {[is_Windows]
- && $::_sh ne {}
- && [file exists [gitexec git-$name]]} {
- # Assume this is a UNIX shell script. We can
- # probably execute it through a Bourne shell.
- #
- set v [list $::_sh [gitexec git-$name]]
+ set p [gitexec git-$name]
+ set f [open $p r]
+ set s [gets $f]
+ close $f
+
+ switch -glob -- $s {
+ #!*sh { set i sh }
+ #!*perl { set i perl }
+ #!*python { set i python }
+ default { error "git-$name is not supported: $s" }
+ }
+
+ upvar #0 _$i interp
+ if {![info exists interp]} {
+ set interp [_which $i]
+ }
+ if {$interp eq {}} {
+ error "git-$name requires $i (not in PATH)"
+ }
+ set v [list $interp $p]