You might want to change the exit 1 in the trap to just exit. This allows the exit code used when the trap was invoked to pass through. Thus if a script aborts with an exit 2 the exit code available to the parent process will be 2. More importantly, if the script exits with a zero (exit 0) that zero (success) is made available to the parent, and the desired cleanup is done.
This is certainly available with Kshell; I assume bash has implemented it as well, but I cannot say.
I'm using the trap command to capture any signals received whilst my script is running.
How's the best way of writing the signal and any other error messages to a file/error log' without having to type '2>$1' on the command line after the script name?
Cheers (3 Replies)
i have the following script that displays the current time until the user presses CTR + c.... but it does not work properly....
Something is not right with the trap command...
Help plz... :confused:
# script to continuously display current time.
# if script is terminated trap signal... (3 Replies)
Dear All
could you please explain me what does the trap command do and how I can write a program which can work as a trap command(in C Language). (1 Reply)
Could anybody tell me what the trap command does and how it performs the action it does. I had read the trap manual page but it is too concise that nothing is clear about it. Please tell how it works. (1 Reply)
Hi,
I would like to know the use of TRAP command. I am very new to the UNIX environment. I have just started learning the basic. So please teach me in a very simple way to understand.
Also i would like to know the use of following command:
trap 'dialog --msgbox "Script Aborted1" 6 50 ;... (2 Replies)
Hi folks,
I have tried to add some trap detection in the below script....this script is used to monitor database activities...in a rather awkward way :rolleyes:....
The idea behind adding trap is that....this script creates lots of temporary files in the running folder to store the count... (1 Reply)
I'm learning about the trap command from my bash book. I tried out the little script they gave:
trap "echo 'You hit control-C!' " INT
while true; do
sleep 60
done
But when I type control-c, the script just stops and the message is not displayed. I checked stty all and saw that control-c... (11 Replies)
dear all;
I can't under stand what does "trap" command do:
for example see below:
trap "echo; echo no interrupts >&2; sleep 3" 2 3 15
Plz , can any body explain the action of this command?
BR (3 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
That is the last reply I received from my instructor, and I'm looking for some alternatives.
When using... (2 Replies)
Hi Folks -
For some reason, my trap command is not working. It's placed just prior to a normal exit:
#:: ------------------------------------------------------------------------
#::-- Script Name: LCM_Backup.sh
#::
#::-- Description: This script leverages Utility.sh to perform LCM... (16 Replies)
Discussion started by: SIMMS7400
16 Replies
LEARN ABOUT X11R4
return
exit(1) User Commands exit(1)NAME
exit, return, goto - shell built-in functions to enable the execution of the shell to advance beyond its sequence of steps
SYNOPSIS
sh
exit [n]
return [n]
csh
exit [ ( expr )]
goto label
ksh
*exit [n]
*return [n]
DESCRIPTION
sh
exit will cause the calling shell or shell script to exit with the exit status specified by n. If n is omitted the exit status is that of
the last command executed (an EOF will also cause the shell to exit.)
return causes a function to exit with the return value specified by n. If n is omitted, the return status is that of the last command exe-
cuted.
csh
exit will cause the calling shell or shell script to exit, either with the value of the status variable or with the value specified by the
expression expr.
The goto built-in uses a specified label as a search string amongst commands. The shell rewinds its input as much as possible and searches
for a line of the form label: possibly preceded by space or tab characters. Execution continues after the indicated line. It is an error to
jump to a label that occurs between a while or for built-in command and its corresponding end.
ksh
exit will cause the calling shell or shell script to exit with the exit status specified by n. The value will be the least significant 8
bits of the specified status. If n is omitted then the exit status is that of the last command executed. When exit occurs when executing
a trap, the last command refers to the command that executed before the trap was invoked. An end-of-file will also cause the shell to exit
except for a shell which has the ignoreeof option (See set below) turned on.
return causes a shell function or '.' script to return to the invoking script with the return status specified by n. The value will be the
least significant 8 bits of the specified status. If n is omitted then the return status is that of the last command executed. If return
is invoked while not in a function or a '.' script, then it is the same as an exit.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO break(1), csh(1), ksh(1), sh(1), attributes(5)SunOS 5.10 15 Apr 1994 exit(1)