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Shell Programming and Scripting

plz explain the execution flow

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Top Forums Shell Programming and Scripting plz explain the execution flow
# 1  
Old 01-21-2010
Bug plz explain the execution flow
CODE

HTML Code:
file=/tmp/rap54ibs2sap.txt
trap "rm $file; exit" 0 1 2 3 15
trap
rm $file
execution result

HTML Code:
trap -- 'rm /tmp/rap54ibs2sap.txt; exit' EXIT
trap -- 'rm /tmp/rap54ibs2sap.txt; exit' SIGHUP
trap -- 'rm /tmp/rap54ibs2sap.txt; exit' SIGINT
trap -- 'rm /tmp/rap54ibs2sap.txt; exit' SIGQUIT
trap -- 'rm /tmp/rap54ibs2sap.txt; exit' SIGTERM
rm: cannot remove `/tmp/rap54ibs2sap.txt': No such file or directory
rm: cannot remove `/tmp/rap54ibs2sap.txt': No such file or directory
if the file doesnot exist then trap will capture the SIGINT and execute "rm $file; exit" which again will try the same operation and again will capture the SIGINT and again insteed of executing "rm $file; exit" and repaet it again and again, why it executes the exit (status must be 0 n signal EXIT) and comes out of the whole statement.
(It should have executed the very statement as again it traps a valid catch)


Plz explain...........
# 2  
Old 01-21-2010
A SIGINT is the "Interrupt Signal", which is sent to the program when you hit CTRL+C (for example). It won't usually get sent to any process just because a file isn't found, and rm surely never sends it.

The reason you're getting the error message twice is that first your regular rm tries to remove a non-existent file, and then the trapped rm is triggered by the pseudo-signal 0, which means EOF.
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