Re: git gui: Possible to see which commands are executed?

["Shawn O. Pearce" <spearce@spearce.org>]

Dirk Ssserott <newsletter@dirk.my1.cc> wrote:
> Is it possible to see which commands are executed by git-gui?
...
> It would be really cool when git-gui could show the command
> in a different window *before* it is executed. Some database
> frontends have an option "show SQL statement", but I think
> that would be demanded too much.

Not presently, no.  People have asked for this in the past, but
its not as easy as it sounds.  git-gui tries to drive the plumbing
commands when possible, not the porcelain that most humans use.
Consequently the stream of commands that git-gui issues is quite
different from what a human would type on the command line, yet
the end result is equivilant.

I hacked this up earlier today on my Cygwin system, just to show you
what I mean.  With the attached patch applied I restarted git-gui
with `git gui --trace` (which this patch introduces) and then used
git-gui to commit this patch to its own repository.

Stop me when you see a command you might type yourself.  ;-)

  C:/cygwin/usr/local/git/bin/git.exe --version
  < git version 1.5.5.1.450.gee27
  C:/cygwin/usr/local/git/bin/git.exe --exec-path
  < /usr/local/git/bin
  C:/cygwin/usr/local/git/bin/git-rev-parse.exe --git-dir
  < .git
  C:/cygwin/usr/local/git/bin/git-rev-parse.exe --show-prefix
  < 
  C:/cygwin/usr/local/git/bin/git-config.exe --null --list
  C:/cygwin/usr/local/git/bin/git-rev-parse.exe --verify HEAD
  < 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/usr/local/git/bin/git-update-index.exe -q --unmerged --ignore-missing --refresh
  C:/cygwin/usr/local/git/bin/git-diff-index.exe --cached -z 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/usr/local/git/bin/git-diff-files.exe -z
  C:/cygwin/usr/local/git/bin/git-ls-files.exe --others -z --exclude-per-directory=.gitignore --exclude-from=.git/info/exclude
  C:/cygwin/usr/local/git/bin/git-rev-parse.exe --verify HEAD
  < 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/usr/local/git/bin/git-update-index.exe -q --unmerged --ignore-missing --refresh
  C:/cygwin/usr/local/git/bin/git-diff-index.exe --cached -z 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/usr/local/git/bin/git-diff-files.exe -z
  C:/cygwin/usr/local/git/bin/git-ls-files.exe --others -z --exclude-per-directory=.gitignore --exclude-from=.git/info/exclude
  C:/cygwin/usr/local/git/bin/git-update-index.exe --add --remove -z --stdin
  C:/cygwin/usr/local/git/bin/git-var.exe GIT_COMMITTER_IDENT
  < Shawn O. Pearce <spearce@spearce.org> 1211130496 -0400
  C:/cygwin/usr/local/git/bin/git-rev-parse.exe --verify HEAD
  < 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/bin/sh.exe -c 'if test -x "$1";then exec "$@";fi'
  C:/cygwin/bin/sh.exe .git/hooks/pre-commit 2>@1
  C:/cygwin/bin/sh.exe -c 'if test -x "$1";then exec "$@";fi'
  C:/cygwin/bin/sh.exe .git/hooks/commit-msg .git/GITGUI_EDITMSG 2>@1
  C:/cygwin/usr/local/git/bin/git-write-tree.exe
  C:/cygwin/usr/local/git/bin/git-cat-file.exe commit 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  C:/cygwin/usr/local/git/bin/git-commit-tree.exe 26a475c0a74f51872513993c41e8e15286df9fa5 -p 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7 <.git/GITGUI_EDITMSG
  < cc33ff6ec3582522edaae00354d9b96a797ecf09
  C:/cygwin/usr/local/git/bin/git-update-ref.exe -m 'commit: git-gui: Add a --trace command line option' HEAD cc33ff6ec3582522edaae00354d9b96a797ecf09 76bb40cde0e15e8d0e8493abb0bd18a5d6386ad7
  < 
  C:/cygwin/bin/sh.exe -c 'if test -x "$1";then exec "$@";fi'
  C:/cygwin/bin/sh.exe .git/hooks/post-commit 2>@1

Right.  So I'm not certain how useful this patch really is.  It is
fairly short as all calls to git go through one of three procedures.


--8<--
git-gui: Add a --trace command line option

---
 git-gui.sh |   47 +++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/git-gui.sh b/git-gui.sh
index 9df4971..6a8831a 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -122,6 +122,14 @@ set _reponame {}
 set _iscygwin {}
 set _search_path {}
 
+set _trace [lsearch -exact $argv --trace]
+if {$_trace >= 0} {
+	set argv [lreplace $argv $_trace $_trace]
+	set _trace 1
+} else {
+	set _trace 0
+}
+
 proc appname {} {
 	global _appname
 	return $_appname
@@ -245,6 +253,21 @@ proc get_config {name} {
 ##
 ## handy utils
 
+proc _trace_exec {cmd} {
+	if {!$::_trace} return
+	set d {}
+	foreach v $cmd {
+		if {$d ne {}} {
+			append d { }
+		}
+		if {[regexp {[ \t\r\n'"$?*]} $v]} {
+			set v [sq $v]
+		}
+		append d $v
+	}
+	puts stderr $d
+}
+
 proc _git_cmd {name} {
 	global _git_cmd_path
 
@@ -339,7 +362,7 @@ proc _lappend_nice {cmd_var} {
 }
 
 proc git {args} {
-	set opt [list exec]
+	set opt [list]
 
 	while {1} {
 		switch -- [lindex $args 0] {
@@ -359,12 +382,18 @@ proc git {args} {
 	set cmdp [_git_cmd [lindex $args 0]]
 	set args [lrange $args 1 end]
 
-	return [eval $opt $cmdp $args]
+	_trace_exec [concat $opt $cmdp $args]
+	set result [eval exec $opt $cmdp $args]
+	if {$::_trace} {
+		puts stderr "< $result"
+	}
+	return $result
 }
 
 proc _open_stdout_stderr {cmd} {
+	_trace_exec $cmd
 	if {[catch {
-			set fd [open $cmd r]
+			set fd [open [concat [list | ] $cmd] r]
 		} err]} {
 		if {   [lindex $cmd end] eq {2>@1}
 		    && $err eq {can not find channel named "1"}
@@ -375,6 +404,7 @@ proc _open_stdout_stderr {cmd} {
 			# to try to start it a second time.
 			#
 			set fd [open [concat \
+				[list | ] \
 				[lrange $cmd 0 end-1] \
 				[list |& cat] \
 				] r]
@@ -387,7 +417,7 @@ proc _open_stdout_stderr {cmd} {
 }
 
 proc git_read {args} {
-	set opt [list |]
+	set opt [list]
 
 	while {1} {
 		switch -- [lindex $args 0] {
@@ -415,7 +445,7 @@ proc git_read {args} {
 }
 
 proc git_write {args} {
-	set opt [list |]
+	set opt [list]
 
 	while {1} {
 		switch -- [lindex $args 0] {
@@ -435,7 +465,8 @@ proc git_write {args} {
 	set cmdp [_git_cmd [lindex $args 0]]
 	set args [lrange $args 1 end]
 
-	return [open [concat $opt $cmdp $args] w]
+	_trace_exec [concat $opt $cmdp $args]
+	return [open [concat [list | ] $opt $cmdp $args] w]
 }
 
 proc githook_read {hook_name args} {
@@ -455,12 +486,12 @@ proc githook_read {hook_name args} {
 		}
 
 		set scr {if test -x "$1";then exec "$@";fi}
-		set sh_c [list | $interp -c $scr $interp $pchook]
+		set sh_c [list $interp -c $scr $interp $pchook]
 		return [_open_stdout_stderr [concat $sh_c $args]]
 	}
 
 	if {[file executable $pchook]} {
-		return [_open_stdout_stderr [concat [list | $pchook] $args]]
+		return [_open_stdout_stderr [concat [list $pchook] $args]]
 	}
 
 	return {}
-- 
1.5.5.1.450.gee27


-- 
Shawn.