util::which (public)
util::which prog
Defined in packages/acs-tcl/tcl/utilities-procs.tcl
Use environment variable PATH to search for the specified executable program. Replacement for UNIX command "which", avoiding exec. exec which: 3368.445 microseconds per iteration ::util::which: 282.372 microseconds per iteration In addition of being more than 10 time faster than the version via exec, this version is less platform dependent.
- Parameters:
- prog - name of the program to be located on the search path
- Returns:
- fully qualified name including path, when specified program is found, or otherwise empty string
- Author:
- Gustaf Neumann
- Partial Call Graph (max 5 caller/called nodes):
- Testcases:
- acs_lang_exec_dependencies, acs_subsite_exec_dependencies, acs_tcl_exec_required_dependencies, acs_tcl_exec_optional_dependencies, file_storage_exec_dependencies
Source code: set key ::acs::which($prog) if {[info exists $key]} { return [set $key] } if {$prog ne ""} { switch -- $::tcl_platform(platform) { windows { # # Notice: Windows has an alternative search environment # via registry. Maybe it is necessary in the future # to locate the program via registry (sketch below) # # package require registry # set key {HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths} # set entries [registry keys $key $prog.*] # if {[llength $entries]>0} { # set fullkey "$key\\[lindex $entries 0]" # return [registry get $fullkey ""] # } # return "" # set searchdirs [split $::env(PATH) \;] set exts [list .exe .dll .com .bat] } default { set searchdirs [split $::env(PATH) :] set exts [list ""] } } set names [lmap ext $exts {set _ $prog$ext}] if {[ad_file pathtype $prog] ne "relative"} { set fullNames $names } else { set fullNames {} foreach dir $searchdirs { foreach name $names { lappend fullNames [ad_file join $dir $name] } } } foreach fullName $fullNames { if {[ad_file executable $fullName]} { return [set $key $fullName] } } } return ""XQL Not present: PostgreSQL, Oracle Generic XQL file: packages/acs-tcl/tcl/utilities-procs.xql