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[PATCHv3 15/16] bash prompt: avoid command substitution when finalizing gitstring

From
SZEDER Gábor <szeder@ira.uka.de>
Date
Jun 24, 2013, 16:39 UTC
Message-ID
<1372091966-19315-16-git-send-email-szeder@ira.uka.de>
In-Reply-To
<1372091966-19315-1-git-send-email-szeder@ira.uka.de>

Before setting $PS1, __git_ps1() uses a command substitution to redirect the output from a printf into a variable. Spare the overhead of fork()ing a subshell by using 'printf -v <var>' to directly assign the output to that variable.

zsh's printf doesn't support the '-v <var>' option, so stick with the command substitution when under zsh.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
---
 contrib/completion/git-prompt.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 5ea6a68b..7152ae49 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -461,7 +461,11 @@ __git_ps1 ()
 		else
 			gitstring="$c${b##refs/heads/}${f:+$z$f}$r$p"
 		fi
-		gitstring=$(printf -- "$printf_format" "$gitstring")
+		if [[ -n ${ZSH_VERSION-} ]]; then
+			gitstring=$(printf -- "$printf_format" "$gitstring")
+		else
+			printf -v gitstring -- "$printf_format" "$gitstring"
+		fi
 		PS1="$ps1pc_start$gitstring$ps1pc_end"
 	else
 		# NO color option unless in PROMPT_COMMAND mode

-- 
1.8.3.1.599.g4459181
Previous: SZEDER GáborNext: SZEDER Gábor
Message 16 of 19 in “[PATCHv3 00/16] bash prompt speedup”
  1. SZEDER GáborJun 24, 2013
  2. 01/16 bash prompt: fix redirection coding style in testsSZEDER Gábor, Jun 24, 2013
  3. 02/16 bash prompt: use 'write_script' helper in interactive rebase testSZEDER Gábor, Jun 24, 2013
  4. 03/16 completion, bash prompt: move __gitdir() tests to completion test suiteSZEDER Gábor, Jun 24, 2013
  5. 04/16 bash prompt: add a test for symbolic link symbolic refsSZEDER Gábor, Jun 24, 2013
  6. 05/16 bash prompt: print unique detached HEAD abbreviated object nameSZEDER Gábor, Jun 24, 2013
  7. 06/16 bash prompt: return early from __git_ps1() when not in a git repositorySZEDER Gábor, Jun 24, 2013
  8. 07/16 bash prompt: run 'git rev-parse --git-dir' directly instead of __gitdir()SZEDER Gábor, Jun 24, 2013
  9. 08/16 bash prompt: use bash builtins to find out rebase stateSZEDER Gábor, Jun 24, 2013
  10. 09/16 bash prompt: use bash builtins to find out current branchSZEDER Gábor, Jun 24, 2013
  11. 10/16 bash prompt: combine 'git rev-parse' executions in the main code pathSZEDER Gábor, Jun 24, 2013
  12. 11/16 bash prompt: combine 'git rev-parse' for detached headSZEDER Gábor, Jun 24, 2013
  13. 12/16 bash prompt: use bash builtins to check for unborn branch for dirty stateSZEDER Gábor, Jun 24, 2013
  14. 13/16 bash prompt: use bash builtins to check stash stateSZEDER Gábor, Jun 24, 2013
  15. 14/16 bash prompt: avoid command substitution when checking for untracked filesSZEDER Gábor, Jun 24, 2013
  16. 15/16 bash prompt: avoid command substitution when finalizing gitstringSZEDER Gábor, Jun 24, 2013
  17. 16/16 bash prompt: mention that PROMPT_COMMAND mode is fasterSZEDER Gábor, Jun 24, 2013
  18. Junio C HamanoJun 24, 2013
  19. Eduardo R. D'AvilaJun 25, 2013

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