If pid is not an active process ID, the wait utility will return immediately and the return code will be 0.
i just came across this which means that wait will returm 0 even though the script has failed so can anyone tell me what is the exact way to get the return status from wait command in bash script ?
Not exactly. If I run the bash script (from a file named nonzero):
I get the output:
The second line of the above output shows that I do get the exit code from a child that died before I called wait as long as its exit status hadn't already been reaped. The line in blue was a diagnostic written by the shell, not directly produced by the script. The final 127 exit status is an indication that you tried to wait for a child that was not your child or that you had already collected its exit status. You will only get a zero exit status if the child whose status wait collected exited with a zero exit status. (Note that if you kill a process and it is catching the signal you sent; it may still exit with a zero exit status.)
These 2 Users Gave Thanks to Don Cragun For This Post:
Ok, heres the situation. We use Solaris 8 and sometimes users who are logged into our system restart their pc's without shutting down the application that attached to our unix backend. I netstat and I get time-waits for the users.
My question is how long before the time-wait ends and the user... (1 Reply)
I have a few xml files and I want to input say 5 parameters within each file. is it possible to do so with sed?
<parameter>A</parameter>
<parameter>B</parameter>
....
....
And so on.
These parameters are meant to go in just inside:
<?xml... (2 Replies)
Hello,
I am trying to write a script that has a option of restarting the script from where it failed. I have to write a script called Batch.sh. This script has to run quite a few sql files as shown below:
logcmd.sh -f test1.sql
logcmd.sh -f test2.sql
logcmd.sh -f test3.sql
logcmd.sh -f... (4 Replies)
:cool:
I need to execute a shell script to do the following:
cat a file
run two back ground processes using the first two values from the file
wait till those background processes finish
run two more background processes using the next two values from the file
wait till those background... (1 Reply)
i have a function defined in one ksh
i want to use the same functionality in another ksh
i am using
. ../<ksh name>
but it is not picking that functionality
what i have to do for the same (2 Replies)
Did not use 'wait' yet.
How I understand by now the wait works only for child processes, started background.
Is there any other way to watch completion of any, not related process (at least, a process, owned by the same user?)
I need to start a background process, witch will be waiting... (2 Replies)
HI,
I have a strange problem. A shell script that runs fine on solaris. when i ported to linux, it started hanging.
here is the core of the script
CFG_FILE=tab25.cfg
sort -t "!" -k 2 ${CFG_FILE} | egrep -v "^#|^$" | while IFS="!" read a b c
do
#echo "jobs output"
#jobs
#echo "jobs... (13 Replies)
Hi,
I am facing a strange issue,
when i call a script from my while loop in background it doesnt go in background, despite the wait i put below the whil loop it goes forward even before the process put in background is completed.
cat abc.txt | while read -u4 line
do
#if line contains #... (2 Replies)
Hi everyone, today i need that someone help to understand this particular line of command.
So you can explain to me step by step, it will be great.
---------- Post updated at 11:53 AM ---------- Previous update was at 11:51 AM ---------- (9 Replies)
Hi ,
I've written the following code to zip the big file
$dir_temp ="/home/etc/hst
zip -r $dir_temp/file_nm.zip $dir_temp/file_nm
The zip file has been created . When I try to UNZIP the file
with the following command
unzip file_nm.zip
The file got unzipped but created in the... (3 Replies)
Discussion started by: smile689
3 Replies
LEARN ABOUT X11R4
wait
wait(1) User Commands wait(1)NAME
wait - await process completion
SYNOPSIS
/bin/sh
wait [pid...]
/bin/jsh /bin/ksh /usr/xpg4/bin/sh
wait [pid...]
wait [ % jobid...]
/bin/csh
wait
DESCRIPTION
The shell itself executes wait, without creating a new process. If you get the error message cannot fork,too many processes, try using the
wait command to clean up your background processes. If this doesn't help, the system process table is probably full or you have too many
active foreground processes. There is a limit to the number of process IDs associated with your login, and to the number the system can
keep track of.
Not all the processes of a pipeline with three or more stages are children of the shell, and thus cannot be waited for.
/bin/sh, /bin/jsh
Wait for your background process whose process ID is pid and report its termination status. If pid is omitted, all your shell's currently
active background processes are waited for and the return code will be 0. The wait utility accepts a job identifier, when Job Control is
enabled (jsh), and the argument, jobid, is preceded by a percent sign (%).
If pid is not an active process ID, the wait utility will return immediately and the return code will be 0.
csh
Wait for your background processes.
ksh
When an asynchronous list is started by the shell, the process ID of the last command in each element of the asynchronous list becomes
known in the current shell execution environment.
If the wait utility is invoked with no operands, it will wait until all process IDs known to the invoking shell have terminated and exit
with an exit status of 0.
If one or more pid or jobid operands are specified that represent known process IDs (or jobids), the wait utility will wait until all of
them have terminated. If one or more pid or jobid operands are specified that represent unknown process IDs (or jobids), wait will treat
them as if they were known process IDs (or jobids) that exited with exit status 127. The exit status returned by the wait utility will be
the exit status of the process requested by the last pid or jobid operand.
The known process IDs are applicable only for invocations of wait in the current shell execution environment.
OPERANDS
The following operands are supported:
One of the following:
pid The unsigned decimal integer process ID of a command, for which the utility is to wait for the termination.
jobid A job control job ID that identifies a background process group to be waited for. The job control job ID notation is applicable
only for invocations of wait in the current shell execution environment, and only on systems supporting the job control option.
USAGE
On most implementations, wait is a shell built-in. If it is called in a subshell or separate utility execution environment, such as one of
the following,
(wait)
nohup wait ...
find . -exec wait ... ;
it will return immediately because there will be no known process IDs to wait for in those environments.
EXAMPLES
Example 1: Using A Script To Identify The Termination Signal
Although the exact value used when a process is terminated by a signal is unspecified, if it is known that a signal terminated a process, a
script can still reliably figure out which signal is using kill, as shown by the following (/bin/ksh and /usr/xpg4/bin/sh):
sleep 1000&
pid=$!
kill -kill $pid
wait $pid
echo $pid was terminated by a SIG$(kill -l $(($?-128))) signal.
Example 2: Returning The Exit Status Of A Process
If the following sequence of commands is run in less than 31 seconds (/bin/ksh and /usr/xpg4/bin/sh):
sleep 257 | sleep 31 &
jobs -l %%
then either of the following commands will return the exit status of the second sleep in the pipeline:
wait <pid of sleep 31>
wait %%
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of wait: LANG, LC_ALL, LC_CTYPE, LC_MES-
SAGES, and NLSPATH.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), jobs(1), ksh(1), sh(1), attributes(5), environ(5), standards(5)SunOS 5.10 12 Dec 1997 wait(1)