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'time' not recognized as reserved when first word after 'if'
From: |
Dale R. Worley |
Subject: |
'time' not recognized as reserved when first word after 'if' |
Date: |
Mon, 9 Jun 2014 20:51:12 -0400 |
Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64'
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-unknown-linux-gnu'
-DCONF_VENDOR='unknown' -DLOCALEDIR='/usr/local/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -g -O2
uname output: Linux hobgoblin.ariadne.com 3.14.4-100.fc19.x86_64 #1 SMP Tue May
13 15:00:26 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-unknown-linux-gnu
Bash Version: 4.3
Patch Level: 0
Release Status: release
Description:
It appears that the reserved word 'time' is not recognized as such if
it is the first word of the command following 'if'. Instead,
/usr/bin/time is executed, producing different output.
Repeat-By:
The reserved word 'time' is to be recognized in certain positions. In
particular, it is to be put at the beginning of a *pipeline*, which
includes the beginnings of *lists*. It does not include any position
in a simple command other than the first word; in particular, it
cannot be after a variable assignment. This is illustrated by:
$ time true
real 0m0.000s <----- built-in output
user 0m0.000s
sys 0m0.000s
$ X=x time true
v----- /usr/bin/time output
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 308maxresident)k
0inputs+0outputs (0major+111minor)pagefaults 0swaps
$ time X=x true
real 0m0.000s <----- built-in output
user 0m0.000s
sys 0m0.000s
However, 'time' is not recognized immediately after 'if', despite that
that position is the beginning of a list, a pipeline, a command, and a
simple command: (The beginning of a pipeline being where the reserved
word 'time' is syntactically allowed, and the beginning of a simple
command being where 'time' is recognized as a reserved word.)
$ if time true ; then echo true ; fi
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 308maxresident)k
0inputs+0outputs (0major+112minor)pagefaults 0swaps
true
But if I add braces around the condition, 'time' is recognized:
(Despite that the condition following 'if' and the contents following
'{' are both 'list'.)
$ if { time true ; } ; then echo true ; fi
real 0m0.000s
user 0m0.000s
sys 0m0.000s
true
Fix:
Unknown.
- 'time' not recognized as reserved when first word after 'if',
Dale R. Worley <=