Sponsored Content
Full Discussion: Shell Variable visibility
Top Forums Shell Programming and Scripting Shell Variable visibility Post 302989511 by Peasant on Friday 13th of January 2017 11:10:03 AM
Old 01-13-2017
In the first example, pipe | creates a subshell outside your current shell to execute a loop.
After the while loop is done, var is 0 in your current shell, since the increment was done in subshell.

The second example increments the var in current shell, so everything is known to the program.

Hope that helps
Regards
Peasant.
These 2 Users Gave Thanks to Peasant For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

set variable with another variable? c shell

okay, this shouldn't be difficult but I can't figure it out. How can I set a variable with another variable. I have the following: foreach pe ($dir $sp) set tpe = `echo $pe | grep M` if ($tpe == M) then set ${$pe} = M <--- This doesn't work else endif end In this case what... (2 Replies)
Discussion started by: wxornot
2 Replies

2. Shell Programming and Scripting

Enviornment Variable in B shell (I call it nested variable)

#!/bin/sh APP_ROOT_MODE1=/opt/app1.0 APP_ROOT_MODE2=/opt/app2.0 APP_ROOT=${APP_ROOT_${APP_MODE}} # enviornment variable APP_MODE will be exported in the terminal where # we run the applciation, its value is string - MODE1 or MODE2 # My intension is: # when export APP_MODE=MODE1... (4 Replies)
Discussion started by: princelinux
4 Replies

3. Shell Programming and Scripting

visibility of a variable in Perl script.

I am writing a script to cross check the dbscript. For that I am searching the SQL manipulators in the dbscript as shown below. But my problem is the variable $pattern is coming as null when comes out of the foreach loop. File content: ========= vi /home2/niroj_p/dbscript.sql -------... (1 Reply)
Discussion started by: Niroj
1 Replies

4. Shell Programming and Scripting

assign awk's variable to shell script's variable?

Dear All, we have a command output which looks like : Total 200 queues in 30000 Kbytes and we're going to get "200" and "30000" for further process. currently, i'm using : numA=echo $OUTPUT | awk '{print $2}' numB=echo $OUTPUT | awk '{print $5}' my question is : can I use just one... (4 Replies)
Discussion started by: tiger2000
4 Replies

5. Shell Programming and Scripting

Shell assign variable to another variable

How can I assign a variable to an variable. IE $car=honda One way I can do it is export $car=honda or let $car=2323 Is there any other ways to preform this task (3 Replies)
Discussion started by: 3junior
3 Replies

6. Shell Programming and Scripting

Not able to store command inside a shell variable, and run the variable

Hi, I am trying to do the following thing var='date' $var Above command substitutes date for and in turn runs the date command and i am getting the todays date value. I am trying to do the same thing as following, but facing some problems, unique_host_pro="sed -e ' /#/d'... (3 Replies)
Discussion started by: gvinayagam
3 Replies

7. Shell Programming and Scripting

[SHELL: /bin/sh] For loop using variable variable names

Simple enough problem I think, I just can't seem to get it right. The below doesn't work as intended, it's just a function defined in a much larger script: CheckValues() { for field in \ Group_ID \ Group_Title \ Rule_ID \ Rule_Severity \ ... (2 Replies)
Discussion started by: Vryali
2 Replies

8. Shell Programming and Scripting

Script to convert csv file to html with good visibility

Hi, I have Below script which converts csv file to html succesfully.but the visiblity is simple in black n white. I want to have better visibilty of each columns in different colours(like green).As it is a Database report suppose some tablespace available space is less than 20% then it should... (7 Replies)
Discussion started by: sv0081493
7 Replies

9. Programming

Visibility of X11 windows

Does anyone know if it is possible to check whether a window in x11 (using xlib) is visible or not? I tried XGetWindowProperty, but that doesn't work, because the windows host (dtwm on Solaris 10) does not support EWMH. (5 Replies)
Discussion started by: JenniferKuiper
5 Replies

10. UNIX for Beginners Questions & Answers

How can I assign awk's variable to shell script's variable?

I have the following script, and I want to assign the output ($10 and $5) from awk to N and L: grdinfo data.grd | awk '{print $10,$5}'| read N L output from gridinfo data.grd is: data.grd 50 100 41 82 -2796 6944 0.016 0.016 3001 2461. where N and L is suppose to be 3001 and 100. I use... (8 Replies)
Discussion started by: geomarine
8 Replies
PIDOF(8)						Linux System Administrator's Manual						  PIDOF(8)

NAME
pidof -- find the process ID of a running program. SYNOPSIS
pidof [-s] [-x] [-o omitpid] [-o omitpid..] program [program..] DESCRIPTION
Pidof finds the process id's (pids) of the named programs. It prints those id's on the standard output. This program is on some systems used in run-level change scripts, especially when the system has a System-V like rc structure. In that case these scripts are located in /etc/rc?.d, where ? is the runlevel. If the system has a start-stop-daemon (8) program that should be used instead. OPTIONS
-s Single shot - this instructs the program to only return one pid. -x Scripts too - this causes the program to also return process id's of shells running the named scripts. -o Tells pidof to omit processes with that process id. The special pid %PPID can be used to name the parent process of the pidof pro- gram, in other words the calling shell or shell script. NOTES
pidof is simply a (symbolic) link to the killall5 program, which should also be located in /sbin. When pidof is invoked with a full pathname to the program it should find the pid of, it is reasonably safe. Otherwise it is possible that it returns pids of running programs that happen to have the same name as the program you're after but are actually other programs. SEE ALSO
shutdown(8), init(8), halt(8), reboot(8) AUTHOR
Miquel van Smoorenburg, miquels@cistron.nl 01 Sep 1998 PIDOF(8)
All times are GMT -4. The time now is 09:30 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy