11-22-2004
I always believe error messages until they are proven wrong. I have to believe that job is suspended because it wants to write on the controlling terminal.
To be more specific, there are two signals used for background processes:
SIGTTIN background process attempting read
SIGTTOU background process attempting write
Both of these deal with reads and writes to the controlling terminal. In the case of a read, there is no option, the signal gets delivered to the process. In the call of a write, this is user configurable. "stty -tostop" will disable the generation of SIGTOU thus allowing a background process to write.
And ZB, are you sure it wasn't "suspended (tty input)"? Both messages can appear and I don't recall a shell mistaking one state for the other. But I don't use tcsh either.
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Ok, so I'm comfortable backgrounding jobs in the shell, starting and stopping them, and bringing them to the fg and bg. What I can't figure out is how to monitor those background jobs from another shell (remote, or local).
Example:
- On a local console for MYHOST, I su to root
- I then update... (3 Replies)
Discussion started by: vikingshelmut
3 Replies
2. Programming
Hi there,
I'm quite new to UNIX for programming. I have a script that does this:
Shows on screen real-time results taken from phone calls and logs them in a file.
However, when I start my script, I want my script to start logging in the file in the background, so I can continue working on... (1 Reply)
Discussion started by: Jeremiorama
1 Replies
3. Shell Programming and Scripting
I have the following sample script to run a script the jobs with the same
priority(in this case field3) in parallel; wait for the jobs to finish
and run the next set of jobs in parallel.When all the lines are read
exit the script.
I have the following script which is doing evrything I want... (1 Reply)
Discussion started by: hyennah
1 Replies
4. Shell Programming and Scripting
i need to execute 5 jobs at a time in background and need to get the exit status of all the jobs i wrote small script below , i'm not sure this is right way to do it.any ideas please help.
$cat run_job.ksh
#!/usr/bin/ksh
####################################
typeset -u SCHEMA_NAME=$1
... (1 Reply)
Discussion started by: GrepMe
1 Replies
5. UNIX for Advanced & Expert Users
Reposting, as it got lost during the database backup. :(
Via a shell script a spawn 3 background jobs namely a, b & c.
These will take different times to complete.
I want to print a different message on completion of each.
How can i find out when each one has completed independently.
... (19 Replies)
Discussion started by: vibhor_agarwali
19 Replies
6. UNIX for Dummies Questions & Answers
If I run a job in the background and logoff. Will the job continue to run or will my processes be killed ? (1 Reply)
Discussion started by: jxh461
1 Replies
7. Shell Programming and Scripting
We had a generic process where the jobs are scheduled to run sequentially and in background. We are noticing the problems with the background jobs.
Error Message:
/bin/ksh: /home/suren/bin/GenericReportScript.sh: cannot execute
The same script is existing in bin and it had enough... (2 Replies)
Discussion started by: sureng
2 Replies
8. Shell Programming and Scripting
Hi All,
Can someone help me in knowing the exact difference between nohup and &.
The definition is quite clear but i only want to know if i run my job using & and in between i hung up my terminal. (10 Replies)
Discussion started by: Uinx_addic
10 Replies
9. Red Hat
I have used shc utillity to convert a shell script to it's compiled version.Inside this script i have called another shell script which is also in compled version.
Example:-
Main script:- main.sh.x
child script:- child.sh.x (this is called inside main.sh.x)
This child script will run in... (2 Replies)
Discussion started by: millan
2 Replies
10. AIX
Hello,
Please advise use of screen in running jobs in nohup background and how to use this
Best regards,
Vishal (1 Reply)
Discussion started by: Vishal_dba
1 Replies
bg(1) General Commands Manual bg(1)
NAME
bg - Runs jobs in the background
SYNOPSIS
bg [job_id...]
Note
The C shell has a built-in version of the bg command. If you are using the C shell, and want to guarantee that you are using the command
described here, you must specify the full path /usr/bin/bg. See the csh(1) reference page for a description of the built-in command.
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
bg: XCU5.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
OPTIONS
None
OPERANDS
Specifies the job to be resumed as a background job. If no job_id operand is given, the most recently suspended job is used. The format of
job_id is described in the Jobs section of the ksh(1) reference page.
DESCRIPTION
If job control is enabled (see the description of set -m in the ksh(1) reference page), the bg utility resumes suspended jobs from the cur-
rent environment by running them as background jobs. If the job specified by job_id is a job already running in the background, the bg
utility has no effect and will exit successfully.
Using bg to place a job into the background causes its process ID to become "known in the current shell execution environment", as if it
had been started as an asynchronous list. See the Jobs section of the ksh(1) reference page.
RESTRICTIONS
If job control is disabled, the bg utility exits with an error and no job is placed in the background. The bg utility does not work as
expected when it is operating in its own utility execution environment because that environment has no suspended jobs.
EXIT STATUS
The following exit values are returned: Successful completion. An error occurred.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of bg: Provides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from the default locale is used. If any of the internationalization vari-
ables contain an invalid setting, the utility behaves as if none of the variables had been defined. If set to a non-empty string value,
overrides the values of all the other internationalization variables. Determines the locale for the interpretation of sequences of bytes
of text data as characters (for example, single-byte as opposed to multibyte characters in arguments). Determines the locale used to
affect the format and contents of diagnostic messages written to standard error. Determines the location of message catalogues for the
processing of LC_MESSAGES.
SEE ALSO
Commands: csh(1), fg(1), jobs(1), kill(1), ksh(1), Bourne shell sh(1b), POSIX shell sh(1p), wait(1)
Standards: standards(5)
bg(1)