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/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -g -O2
uname output: Linux eccles 2.6.35-rc6 #1 SMP Fri Jul 23 11:52:29 BST 2010
x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-unknown-linux-gnu
Bash Version: 4.1
Patch Level: 2
Release Status: release
Description:
Incrementing a variable with ((count++)), which should access the value
in the variable and then increment it by 1 has some strange behaviour.
In some situations it seems to increment the variable before accessing
it, and in others it increments it by 2
Repeat-By:
Make an array to work with:
andy:~$ days=({Mon,Tues,Wednes,Thurs,Fri,Satur,Sun}day)
andy:~$ echo ${da...@]}
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
So far, so good. Now try to access the array by stepping through it with
((count++))
andy:~$ count=0
andy:~$ echo "${days[$((count++))]}, ${days[$((count++))]},
${days[$((count++))]}"
Monday, Tuesday, Wednesday
Also good. Now try converting it to lower case with ,,
andy:~$ count=0
andy:~$ echo "${days[${count}],,}, ${days[$((count++))],,},
${days[$((count++))],,}"
monday, tuesday, thursday
What happened to wednesday?
Andy
