Sponsored Content
Top Forums Shell Programming and Scripting Bash script parallel tasks and command to wait untill complete? Post 302894978 by pludi on Friday 28th of March 2014 07:15:46 AM
Old 03-28-2014
From the man page:
Quote:
wait [n ...]
Wait for each specified process and return its termination status. Each n may be a process ID or a job specification; if a job spec is given, all processes in that job's pipeline are waited for. If n is not given, all currently active child processes are waited for, and the return status is zero. If n specifies a non-existent process or job, the return status is 127. Otherwise, the return status is the exit status of the last process or job waited for.
 

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

PERL: wait for process to complete

I'm using PERL on windows NT to try to run an extract of data. I have multiple zip files in multiple locations. I am extracting "*.t" from zip files and subsequently adding that file to one zip file so when the script is complete I should have one zip file with a whole bunch of ".t" files in it. ... (2 Replies)
Discussion started by: dangral
2 Replies

2. Shell Programming and Scripting

Wait for Background Process to complete

I am attempting within a for-loop, to have my shell script (Solaris v8 ksh) wait until a copy file command to complete before continueing. The specific code is: for files in $(<inputfile.lst) do mv directory/$files directory/$files ksh -m -i bg %% wait $! done I am shaky on the... (3 Replies)
Discussion started by: gozer13
3 Replies

3. UNIX for Dummies Questions & Answers

BASH complete-filename & menu-complete together

Hi, Does anyone know how to make BASH provide a list of possible completions on the first tab, and then start cycling through the possibilites on the next tab? Right now this is what I have in my .bashrc: bind "set show-all-if-ambiguous on" bind \\C-o:menu-complete This allows... (0 Replies)
Discussion started by: Mithu
0 Replies

4. Filesystems, Disks and Memory

hdparm + HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl

Hi All, Am finding performance of my SD card using hdparm. hdparm -tT /dev/BlockDev0 /dev/BlockDev0: Timing cached reads: 1118 MB in 2.00 seconds = 558.61 MB/sec HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device Timing buffered disk reads: 14... (0 Replies)
Discussion started by: amio
0 Replies

5. UNIX for Dummies Questions & Answers

How do you wait for command substitution processes to complete?

When running a command using the >(cmd) syntax in bash how do you wait for the command to complete before moving on in your script? Here is a simple example: zcat largefile.gz | tee >(wc && echo “HELLO”) > /dev/null # I tried wait, here but it doesn't wait for the process in the subshell.... (8 Replies)
Discussion started by: mrvwman
8 Replies

6. Shell Programming and Scripting

Line in bash script to wait for x feedbacks and then continue

I have a script that runs a console/terminal command on the server and what is want is for each of the multiple success reports fed back from the clients (echo-ed out onto the conosle) to be counted and after x number of reports reboot the server. The Details: The command (program) is... (0 Replies)
Discussion started by: dp123
0 Replies

7. Shell Programming and Scripting

Wait for one processes to complete in a shell script

Let's say I start process A.sh, then start process B.sh. I call both of them in my C.sh How can I make sure that B starts its execution only after A.sh finishes. I have to do this in loop.Execution time of A.sh may vary everytime. It is a parameterized script. (17 Replies)
Discussion started by: rafa_fed2
17 Replies

8. Shell Programming and Scripting

In Shell Script Does Second Command Wait For First Command To Complete

Hi All, I have a question related to Shell scripting. In my shell script, I have following two commands in sequence: sed 's/^/grep "^120" /g' $ORIGCHARGEDAMTLIST|sed "s;$;| cut -f$FIELD_NO1 -d '|' | awk '{ sum+=\$1} END {printf (\"%0.2f\\\n\", sum/100)}' >$TEMPFILE mv $TEMPFILE $ORIGFILE... (3 Replies)
Discussion started by: angshuman
3 Replies

9. Shell Programming and Scripting

(bash) Script Processes in Parallel

Hello all, I tried to parralise my treatments but after a while 'ps -ef' display all child process <defunct> (zombie) Parent bash script to process all files (>100000) in directory: for filename in /Data/*.txt; do ./child_pprocess.sh $filename & done exit(0)I understand that the... (1 Reply)
Discussion started by: namnetes
1 Replies
WAIT(2) 						      BSD System Calls Manual							   WAIT(2)

NAME
wait, waitpid, wait4, wait3 -- wait for process termination LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <sys/types.h> #include <sys/wait.h> pid_t wait(int *status); #include <sys/time.h> #include <sys/resource.h> pid_t waitpid(pid_t wpid, int *status, int options); pid_t wait3(int *status, int options, struct rusage *rusage); pid_t wait4(pid_t wpid, int *status, int options, struct rusage *rusage); DESCRIPTION
The wait() function suspends execution of its calling process until status information is available for a terminated child process, or a sig- nal is received. On return from a successful wait() call, the status area contains termination information about the process that exited as defined below. The wait4() system call provides a more general interface for programs that need to wait for certain child processes, that need resource uti- lization statistics accumulated by child processes, or that require options. The other wait functions are implemented using wait4(). The wpid argument specifies the set of child processes for which to wait. If wpid is -1, the call waits for any child process. If wpid is 0, the call waits for any child process in the process group of the caller. If wpid is greater than zero, the call waits for the process with process id wpid. If wpid is less than -1, the call waits for any process whose process group id equals the absolute value of wpid. The status argument is defined below. The options argument contains the bitwise OR of any of the following options. The WCONTINUED option indicates that children of the current process that have continued from a job control stop, by receiving a SIGCONT signal, should also have their status reported. The WNOHANG option is used to indicate that the call should not block if there are no processes that wish to report status. If the WUNTRACED option is set, children of the current process that are stopped due to a SIGTTIN, SIGTTOU, SIGTSTP, or SIGSTOP signal also have their status reported. The WSTOPPED option is an alias for WUNTRACED. The WNOWAIT option keeps the process whose status is returned in a waitable state. The process may be waited for again after this call completes. If rusage is non-zero, a summary of the resources used by the terminated process and all its children is returned (this information is cur- rently not available for stopped or continued processes). When the WNOHANG option is specified and no processes wish to report status, wait4() returns a process id of 0. The waitpid() function is identical to wait4() with an rusage value of zero. The older wait3() call is the same as wait4() with a wpid value of -1. The following macros may be used to test the manner of exit of the process. One of the first three macros will evaluate to a non-zero (true) value: WIFCONTINUED(status) True if the process has not terminated, and has continued after a job control stop. This macro can be true only if the wait call specified the WCONTINUED option). WIFEXITED(status) True if the process terminated normally by a call to _exit(2) or exit(3). WIFSIGNALED(status) True if the process terminated due to receipt of a signal. WIFSTOPPED(status) True if the process has not terminated, but has stopped and can be restarted. This macro can be true only if the wait call specified the WUNTRACED option or if the child process is being traced (see ptrace(2)). Depending on the values of those macros, the following macros produce the remaining status information about the child process: WEXITSTATUS(status) If WIFEXITED(status) is true, evaluates to the low-order 8 bits of the argument passed to _exit(2) or exit(3) by the child. WTERMSIG(status) If WIFSIGNALED(status) is true, evaluates to the number of the signal that caused the termination of the process. WCOREDUMP(status) If WIFSIGNALED(status) is true, evaluates as true if the termination of the process was accompanied by the creation of a core file containing an image of the process when the signal was received. WSTOPSIG(status) If WIFSTOPPED(status) is true, evaluates to the number of the signal that caused the process to stop. NOTES
See sigaction(2) for a list of termination signals. A status of 0 indicates normal termination. If a parent process terminates without waiting for all of its child processes to terminate, the remaining child processes are assigned the parent process 1 ID (the init process ID). If a signal is caught while any of the wait() calls are pending, the call may be interrupted or restarted when the signal-catching routine returns, depending on the options in effect for the signal; see discussion of SA_RESTART in sigaction(2). The implementation queues one SIGCHLD signal for each child process whose status has changed, if wait() returns because the status of a child process is available, the pending SIGCHLD signal associated with the process ID of the child process will be discarded. Any other pending SIGCHLD signals remain pending. If SIGCHLD is blocked, wait() returns because the status of a child process is available, the pending SIGCHLD signal will be cleared unless another status of the child process is available. RETURN VALUES
If wait() returns due to a stopped, continued, or terminated child process, the process ID of the child is returned to the calling process. Otherwise, a value of -1 is returned and errno is set to indicate the error. If wait4(), wait3(), or waitpid() returns due to a stopped, continued, or terminated child process, the process ID of the child is returned to the calling process. If there are no children not previously awaited, -1 is returned with errno set to ECHILD. Otherwise, if WNOHANG is specified and there are no stopped, continued or exited children, 0 is returned. If an error is detected or a caught signal aborts the call, a value of -1 is returned and errno is set to indicate the error. ERRORS
The wait() function will fail and return immediately if: [ECHILD] The calling process has no existing unwaited-for child processes. [ECHILD] No status from the terminated child process is available because the calling process has asked the system to discard such status by ignoring the signal SIGCHLD or setting the flag SA_NOCLDWAIT for that signal. [EFAULT] The status or rusage argument points to an illegal address. (May not be detected before exit of a child process.) [EINTR] The call was interrupted by a caught signal, or the signal did not have the SA_RESTART flag set. SEE ALSO
_exit(2), ptrace(2), sigaction(2), exit(3), siginfo(3) STANDARDS
The wait() and waitpid() functions are defined by POSIX; wait4() and wait3() are not specified by POSIX. The WCOREDUMP() macro and the abil- ity to restart a pending wait() call are extensions to the POSIX interface. HISTORY
The wait() function appeared in Version 6 AT&T UNIX. BSD
November 12, 2005 BSD
All times are GMT -4. The time now is 07:50 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy