Sponsored Content
Full Discussion: Confusion with PS
Top Forums Shell Programming and Scripting Confusion with PS Post 302706645 by Lem on Thursday 27th of September 2012 05:50:53 AM
Old 09-27-2012
Quote:
Originally Posted by pamu
Just one question. from where you are getting $0?
If I understand correctly, he runs these commands from inside a script.

However, see my script, named "file":

Code:
#!/bin/bash
echo $0
ps axu |head -n 1 # this is to see ps headers
ps axu | grep $0 | grep -v grep | tee /dev/tty |wc -l
ps axu | grep $0 | grep -v grep  |tee /dev/tty |wc -l

If I run it, most of the time I get:
Code:
lem@biggy:/tmp$ ./file
./file
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
lem      25757  0.0  0.0  18584  1432 pts/3    S+   11:44   0:00 /bin/bash ./file
1
lem      25757  0.0  0.0  18584  1432 pts/3    S+   11:44   0:00 /bin/bash ./file
1

Very few times I get instead:
Code:
lem@biggy:/tmp$ ./file
./file
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
lem      25770  0.0  0.0  18584  1428 pts/3    S+   11:44   0:00 /bin/bash ./file
1
lem      25770  0.0  0.0  18584  1428 pts/3    S+   11:44   0:00 /bin/bash ./file
lem      25779  0.0  0.0  18584   432 pts/3    R+   11:44   0:00 /bin/bash ./file
2

The first ps always gives me one process, the second ps seldom gives two.
--
Bye
 

9 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

unix confusion

:confused: some one please tell me where i can possibly find out what is unix 10.2 and the basic system functions of it is. I really need help! (1 Reply)
Discussion started by: tribb24
1 Replies

2. UNIX for Dummies Questions & Answers

'tr' confusion

Good day, everyone! Could anybody explain me the following situation. If I'm running similar script: Var="anna.kurnikova" Var2="Anna Kurn" echo $Var | tr -t "$Var" "$Var2" Why the output is : anna KurniKova instead of Anna Kurnikova? :confused: Thank you in advance for any... (2 Replies)
Discussion started by: Nafanja
2 Replies

3. UNIX for Dummies Questions & Answers

crontab confusion

I come across an entry in cron which is in such: 0 * * * * What is the first 0 indicating? 0 minute? meaning a script cron as such will run every minute? :confused: (2 Replies)
Discussion started by: user50210
2 Replies

4. Programming

C fork Confusion :-?

Hi, I was trying to learn forking in C in UNIX. Somehow i still haven't been able to get the concept well. I mean, i do understand that fork creates an exact replica of the parent (other than the fact that parent gets the process id of the child and child gets 0 when fork is called). This is the... (2 Replies)
Discussion started by: ralpheno
2 Replies

5. Shell Programming and Scripting

conditional confusion

Hell Unix.com Community: I am working on a personal project using yad v0.12.4 (zenity fork) and have hit a wall on how to show a progress bar while my function is processing. I have been all over the ABS Guide, googled 21 Linux-specific sites that I revere. I even asked on the yad-common... (4 Replies)
Discussion started by: Habitual
4 Replies

6. Programming

shmget confusion?????

Hi friends, This is a small program built on the concept of shared memory. The producer is a separate program and process, and the consumer is a seperate program and process. Both are executed under the same user account. The producer takes some string from the user and adds that string to the... (1 Reply)
Discussion started by: gabam
1 Replies

7. Homework & Coursework Questions

Server Confusion

I don't even know where to start with this one. There is so much out there about different aspects of this. I am starting with a basic Ubuntu 11.04 install. Do I need to configure a DNS? I am a little confused about that. What do I need to do for a domain name? I have followed various tutorials,... (1 Reply)
Discussion started by: polyglot0727
1 Replies

8. Shell Programming and Scripting

confusion in use of exit 0

hi i am new to shell scripting. i was going thru the part option and arguments. on this section i fail to understand the use of exit 0 in below example . #!/bin/sh USAGE="Usage: $0 " case "$1" in -t) TARGS="-tvf $2" ;; -c) TARGS="-cvf $2.tar $2" ;; *) echo "$USAGE" exit 0 ;; esac... (13 Replies)
Discussion started by: scriptor
13 Replies

9. Shell Programming and Scripting

Confusion in hash

Hi folks, If a declare a direct hash , then the hash element works fine. my %test = ("test",1); print %test; print "\n"; Here in the above, the name of the hash is predeclared... Suppose now I need to create the hash elements dynamically in the for loop. $test="hash"; my... (1 Reply)
Discussion started by: scriptscript
1 Replies
VM(1)								      mgetty								     VM(1)

NAME
vm - VoiceModem is the program for handling the voice modem functionality from shell scripts ACTIONS
beep options [<frequency [<length in 0.001sec>]]> diagnostics options device name (e.g. ttyS2 dial options phone number help play options [<file names]+> record options file name shell options [<shell script [shell options]]> wait options [<time in seconds]> devicetest OPTIONS
-c n use compression type n -d n set i/o device -t, -m, -i, -e, -s, -H equals to -d <2,3,4,5,6,7> -l s set device string (e.g. -l ttyS2:ttyC0) -v verbose output -w use off / on hook signal from local handset to start and stop recording -x n set debug level -L n set maximum recording length in sec -P print first DTMF tone on stdout and exit -R read and print DTMF string on stdout and exit -S s set default shell for shell scripts (e.g. -S /bin/sh) -T n set silence timeout in 0.1sec -V n set silence threshold to <n> (0-100%%) SEE ALSO
vgetty(1) POD ERRORS
Hey! The above document had some coding errors, which are explained below: Around line 30: You forgot a '=back' before '=head1' Around line 32: '=item' outside of any '=over' Around line 71: You forgot a '=back' before '=head1' perl v5.10.1 2010-04-04 VM(1)
All times are GMT -4. The time now is 09:10 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy