Sponsored Content
Full Discussion: ps command returns a "?"
Top Forums UNIX for Dummies Questions & Answers ps command returns a "?" Post 302090223 by Perderabo on Saturday 23rd of September 2006 03:05:20 PM
Old 09-23-2006
Quote:
Originally Posted by reborg
Just to illustrate what Perderabo has
Code:
(  tail -f /var/log/syslog & )
#exit from session

The tail -f will continue to run without a tty.
This is a different case than what I had in mind and more explanation is in order. When a session leader with a controlling terminal exits, the terminal is yanked away from the session. Posix demands that a HUP be delivered to the foreground process group. Also, suppose that a background job had been suspended because it wanted tty input. There will be no way for it to resume. So if any process a background process group is stopped, the entire group will be sent a HUP followed by a CONT. Some OS's will send a HUP to all background processes. Regardless, a process can ignore HUP and continue to function. Any process groups that continue to run after the session leader has exited are called orphaned. A member of a orphaned process group cannot read nor write to its controlling terminal nor will it recieve any signals from key presses on the terminal. However with most OS's, the controlling terminal remains open and this may show up in the ps output. The close() system call is supposed to succeed although any buffered data is discarded.

As this page says:
Quote:
The terminal-driver repeatedly does the foreground/background/orphaned process-group check whenever a process tries to access the terminal.
Poor jxh461 probably is beginning to regret the question. Smilie
 

10 More Discussions You Might Find Interesting

1. Programming

pthread_create returns "operation not permitted" if I try to link static?

Hello, I am trying to port some testtools we wrote from solaris to redhat linux(AMD64). If I link dynamic, set the correct LD_LIBRARY_PATH, everything runs fine. If I try to link static, the pthread_create returns "operation not permitted" (error code 1). Does anybody have an idea where to... (1 Reply)
Discussion started by: Micky
1 Replies

2. UNIX for Dummies Questions & Answers

diff on c-source file always returns "files differ"

I have a c-source file that is evidently seen by unix as a binary file. When doing a diff between it and older versions with substantial differences, diff will only return "files differ". I have tried cat-ing the file to another file; tried using the "-h" on the diff; I have tried ftp-ing it... (7 Replies)
Discussion started by: C-Prog-Man
7 Replies

3. Shell Programming and Scripting

if returns "unknown test operator"

Greetings, using ksh on Solaris, I am trying to identify the current version of a package installed on multiple servers using if statement in a precursor to upgrading. I have searched the forums and have found many hits, reviewed 3 pages and have tried the different variations noted there. Also... (3 Replies)
Discussion started by: 22blaze
3 Replies

4. UNIX for Dummies Questions & Answers

Command Character size limit in the "sh" and "bourne" shell

Hi!!.. I would like to know what is maximum character size for a command in the "sh" or "bourne" shell? Thanks in advance.. Roshan. (1 Reply)
Discussion started by: Roshan1286
1 Replies

5. Shell Programming and Scripting

Command Character size limit in the "sh" and "bourne" shell

Hi!!.. I would like to know what is maximum character size for a command in the "sh" or "bourne" shell? Thanks in advance.. Roshan. (1 Reply)
Discussion started by: Roshan1286
1 Replies

6. Shell Programming and Scripting

awk command to replace ";" with "|" and ""|" at diferent places in line of file

Hi, I have line in input file as below: 3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL My expected output for line in the file must be : "1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL" Can someone... (7 Replies)
Discussion started by: shis100
7 Replies

7. Solaris

Checking RAID health, metastat returns "no database"

Hello, I am supposed to check the RAID health of a system but when I type metastat it says "there are no existing databases" Does this mean that there is no RAID configured at all? Is there any other utility I should try? I know the system has two disks. Tanks! (8 Replies)
Discussion started by: cevspencer
8 Replies

8. Shell Programming and Scripting

sed returns error "sed: -e expression #1, char 18: unterminated `s' command"

Hello All, I have something like below LDC100/rel/prod/libinactrl.a LAA2000/rel/prod/libinactrl.a I want to remove till first forward slash that is outputshould be as below rel/prod/libinactrl.a rel/prod/libinactrl.a How can I do that ??? (8 Replies)
Discussion started by: anand.shah
8 Replies

9. Shell Programming and Scripting

Source command returns error when it strikes conditional statement "ifeq"

Hello All, I am running source command on my project configuration file app.cfg which has conditional statements with make file systax E.g ifeq ($(APP_CMP_DIR),trunk). When I source this file it throws error: syntax error near unexpected token... (1 Reply)
Discussion started by: anand.shah
1 Replies

10. UNIX for Dummies Questions & Answers

Using "mailx" command to read "to" and "cc" email addreses from input file

How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address and column 3 contains “cc” e-mail address to include with same email. Sample input file, email.txt Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies
PTS_SLEEP(1)						       AFS Command Reference						      PTS_SLEEP(1)

NAME
pts_sleep - Pauses for a few seconds SYNOPSIS
pts sleep [-delay] <# of seconds> [-cell] <cell name> [-noauth] [-localauth] [-force] pts sl [-d] <# of seconds> [-c] <cell name> [-n] [-l] [-f] DESCRIPTION
The pts sleep pauses for a specified number of seconds. The command can be run from the command line or interactively, although from the command line it's essentially equivalent to the sleep command. It is intended for use in interactive mode to pause for a few seconds between batch commands to allow the Protection Server to catch up. CAUTIONS
Prior to OpenAFS 1.4.5 and OpenAFS 1.5.23, the pts sleep command was only available on Unix or Linux and when OpenAFS was compiled with the supergroups option (disabled by default). As of OpenAFS 1.4.5 and 1.5.23, it is always available. OPTIONS
Although they have no effect, pts sleep takes the following standard pts options: -cell <cell name> Names the cell in which to run the command. For more details, see pts(1). -force Enables the command to continue executing as far as possible when errors or other problems occur, rather than halting execution at the first error. -help Prints the online help for this command. All other valid options are ignored. -localauth Constructs a server ticket using a key from the local /etc/openafs/server/KeyFile file. Do not combine this flag with the -cell or -noauth options. For more details, see pts(1). -noauth Assigns the unprivileged identity anonymous to the issuer. For more details, see pts(1). OUTPUT
This command produces no output. EXAMPLES
Here is an example of a pts interactive session: % pts interactive pts> sleep 5 pts> quit % SEE ALSO
pts(1), pts_interactive(1) COPYRIGHT
Copyright 2007 Jason Edgecombe <jason@rampaginggeek.com> This documentation is covered by the BSD License as written in the doc/LICENSE file. This man page was written by Jason Edgecombe for OpenAFS. OpenAFS 2014-04-08 PTS_SLEEP(1)
All times are GMT -4. The time now is 12:38 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy