Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: What does this do in bash: ${pid:-}
Top Forums Shell Programming and Scripting What does this do in bash: ${pid:-} Post 302246003 by otheus on Sunday 12th of October 2008 08:28:01 AM
Old 10-12-2008
Granted, null and zero-length are different, but the shell expands them the same way. So really there's no reason for the code as is. It could simply be:
Code:
if [ -z "$pidfile" ] ;then 
  # blah blah
fi

There's actually a simpler way.
Code:
pidfile=${pidfile:-/var/run/${1##*/}.pid}

 

10 More Discussions You Might Find Interesting

1. Programming

printing ppid,child pid,pid

question: for the below program i just printed the value for pid, child pid and parent pid why does it give me 6 values? i assume ppid is 28086 but can't figure out why there are 5 values printed instead of just two! can someone comment on that! #include<stdio.h> #define DIM 8 int... (3 Replies)
Discussion started by: a25khan
3 Replies

2. Shell Programming and Scripting

how to get PID only

The below command returns full line.How can i get only PID from this line ie 15794 from the below example (FI NY) nbswpsa52.ny.ficc.gs.com~ ->ps -ef | grep keepalive | grep -v keepaliveStub | grep -v swapback | grep -v grep ficctprd 15794 1 0 13:12:58 ? 0:01 keepalive (3 Replies)
Discussion started by: kotasateesh
3 Replies

3. Shell Programming and Scripting

PID in BASH

In a shell script, in need to execute a proccess in background, do some jobs then kill that process. ie, someproc parameter1 & somescript.sh kill pid_of_the_proc_in_the_first_line How can can get the PID of the process I'm invoking in the first line? (1 Reply)
Discussion started by: rayne
1 Replies

4. UNIX for Dummies Questions & Answers

Session PID & socket connection pid

1. If I use an software application(which connects to the database in the server) in my local pc, how many PID should be registered? Would there be PID for the session and another PID for socket connection? 2. I noticed (through netstat) that when I logged in using the my software application,... (1 Reply)
Discussion started by: pcx26
1 Replies

5. Shell Programming and Scripting

KILL PID, intern should kill another PID.

Hi All, In my project i have two process runs in the back end. Once i start my project, and execute the command ps, i get below output: PID TTY TIME CMD 9086 pts/1 0:00 ksh 9241 pts/1 0:02 java 9240 pts/1 0:00 shell_script_bg java with 9241 PID is the main... (4 Replies)
Discussion started by: rkrgarlapati
4 Replies

6. UNIX for Dummies Questions & Answers

Need to get pid of a process and have to store the pid in a variable

Hi, I need to get the pid of a process and have to store the pid in a variable and i want to use this value(pid) of the variable for some process. Please can anyone tell me how to get the pid of a process and store it in a variable. please help me on this. Thanks in advance, Amudha (7 Replies)
Discussion started by: samudha
7 Replies

7. UNIX for Dummies Questions & Answers

Get pid

Hello people, This question might seem to be a little naive but here it goes: I want to know the PID of a script that is running in the background. eg: There is a script called Data_Downloader.sh I am using the command: ps -ef | grep Data_Downloader.sh But I am getting the output as wrkarea... (9 Replies)
Discussion started by: Rajat
9 Replies

8. UNIX for Dummies Questions & Answers

Another PID ?

I have searched to find an anwer to no avail, I hope you can help me. I have a.ksh that many people call and a.ksh calls b.ksh b.ksh is also invoked stand-alone by many people as well In b.ksh I want to do something different if it was not involked by a.ksh. How can I do this? (7 Replies)
Discussion started by: CAGIRL
7 Replies

9. UNIX for Dummies Questions & Answers

Write pid and command name to a txt file while executing a bash script

Hi All, Just have a requirement, I am executing a bash shell script, my requirement is to catch the pid and job name to a txt file in the same directory, is there anyway to do it? please help me out. Regards Rahul ---------- Post updated at 08:42 AM ---------- Previous update was at... (2 Replies)
Discussion started by: rahulkalra9
2 Replies

10. UNIX for Dummies Questions & Answers

Login PID in sh/bash different

In bourne shell the PID generated for the command "ps" matches my login id PID in the command "who -Hu" but in bash/linux the PID generated with the same commands are different . Why so? (2 Replies)
Discussion started by: asd78in
2 Replies

LEARN ABOUT DEBIAN

udisks-glue

UDISKS-GLUE(1)							udisks-glue Manual						    UDISKS-GLUE(1)

NAME

       udisks-glue - A tool to associate udisks events to user-defined actions

SYNOPSIS

       udisks-glue [-c config-file] [-f] [-p pidfile] [-s]
       udisks-glue [-h]

DESCRIPTION

       udisks-glue  listens for UDisks DBus events and reacts to them according to the configuration. It can be used to automatically mount remov-
       able devices or perform arbitrary actions in response to events related to removable devices.

OPTIONS

       -c/--config config-file	 Use config-file as the configuration file

       -f/--foreground		 Remain in foreground (don't daemonize)

       -h/--help		 Display usage information and exit

       -p/--pidfile pidfile	 Use pidfile file as the pidfile

       -s/--session		 Enable ConsoleKit session support

FILES

       A configuration file must exist or udisks-glue will fail to start up. If no configuration file is  specified  by  command  line	arguments,
       udisks-glue will look for the following configuration files (in this order):

       1. $HOME/.udisks-glue.conf

       2. $XDG_CONFIG_HOME/udisks-glue/config

       3. /etc/udisks-glue.conf

       4. $DIR/udisks-glue/config for each dir in $XDG_CONFIG_DIRS

SEE ALSO

       udisks(1), udisks-glue.conf(5) udisks(7), udisks-daemon(8)

udisks-glue							    2011-04-20							    UDISKS-GLUE(1)
All times are GMT -4. The time now is 10:58 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy