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-redhat-linux-gnu' -DCONF_VENDOR='redhat' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL -DHAVE_CONFIG_H -I. -I. -I./include -I./lib -D_GNU_SOURCE -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic uname output: Linux adenine.physics.iisc.ernet.in 2.6.21-1.3194.fc7 #1 SMP Wed May 23 22:47:07 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux Machine Type: x86_64-redhat-linux-gnu
Bash Version: 3.2 Patch Level: 33 Release Status: release Description: [Detailed description of the problem, suggestion, or complaint.] Logically equivalent statements output different results. Suspect problem with 'pipe'. Let there be two files - a and b. #---number of lines in a is 2--- echo "0 0" > a #---number of lines in b is 3--- echo "0 0 0" > b; p=0; for lig in `cat a`; do for i in `cat b`; do echo "printing $p"; ((p=$p+1)); done; done #outputs printing 0 printing 1 printing 2 printing 3 printing 4 printing 5 p=0; for lig in `cat a`; do cat b | while read i; do echo "printing $p"; ((p=$p+1)); done; done #outputs (I DO NOT EXPECT p TO BE RESET EACH TIME WHILE RUNS) printing 0 printing 1 printing 2 printing 0 printing 1 printing 2 Repeat-By: [Describe the sequence of events that causes the problem to occur.] Above statements can be executed in terminal for reproduction of the problem.