Sponsored Content
Top Forums Programming Unix Shell background processing Post 302457328 by Corona688 on Monday 27th of September 2010 07:13:46 PM
Old 09-27-2010
Quote:
Originally Posted by Mercfh
BTW, totally off topic, but is there any reason cd (change dir.) doesn't ever work on any of these "sample shells" i've seen around (when I was looking for help with mine, i looked at a ton of examples and tried a ton of them) is their something special about cd?
Seems quite on-topic to me.

cd is special because it's not a command you run, it's the system call chdir(), and it has to be done inside the shell itself, not in a forked copy. Remember that the forked copy is independent. If you chdir inside it, your original shell still remains where it is, defeating the point!

So the shell has to handle cd itself, feeding its parameters into the chdir() call directly, not forking anything.
This User Gave Thanks to Corona688 For This Post:
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

background for unix

Hi, I am a newbie learing Unix , I have started with teh book "the Design of the Unix OS" by Bach.After which I plan to read "UNIX Network Programming" by Richard Stevens. What is the background that one needs to learn unix. I know C. But I am not sure about my Operating Systems... (4 Replies)
Discussion started by: ramyar
4 Replies

2. UNIX Desktop Questions & Answers

Unix Background

Hi, I'm new to this forums and to Unix OS... Is this the right place to put this thread? I just need to ask how to set the wallpaper that goes through the x-term windows in a Unix system? It's as if the x-term windows is transparent... I tried modifying the .login file and things got... (5 Replies)
Discussion started by: Gri3v3r7
5 Replies

3. Shell Programming and Scripting

Background shell script

I have a friend at work that asked me a question today and I figured I would seek help here. How does a shell script know whether it is running in the background or not? Thanks in advance for help (5 Replies)
Discussion started by: Moofasa
5 Replies

4. Shell Programming and Scripting

run a shell in the background

How can I run a shell in the background? cat test.sh #!/bin/sh sleep 600 Thank u very much indeed! (2 Replies)
Discussion started by: GCTEII
2 Replies

5. Linux

background processing in BASH

I have script 3 scripts 1 parent 2 children child1 child2 In the code below the 2 child processes fire almost Instantaneously in the background, Is that possible to know the status of pass/fail of each process "as it happens" ? In the present scenario although Child2... (5 Replies)
Discussion started by: jville
5 Replies

6. Shell Programming and Scripting

background processing in BASH

I have script 3 scripts 1 parent (p1) and 2 children child1 and child2 I have script 3 scripts 1 parent 2 children child1 child2 In the code below the 2 child processes fire almost Instantaneously in the background, Is that possible to know the status of pass/fail of each process... (12 Replies)
Discussion started by: jville
12 Replies

7. Shell Programming and Scripting

BASH - Handling background processes - distributed processing

NOTE: I am using BASH and Solaris 10 for this. Currently in the process of building a script that has a main "watcher" daemon that reads a configuration file and starts background processes based on it's global configuration. It is basically an infinite loop of configuration reading. Some of the... (4 Replies)
Discussion started by: dcarrion87
4 Replies

8. Programming

awk processing / Shell Script Processing to remove columns text file

Hello, I extracted a list of files in a directory with the command ls . However this is not my computer, so the ls functionality has been revamped so that it gives the filesizes in front like this : This is the output of ls command : I stored the output in a file filelist 1.1M... (5 Replies)
Discussion started by: ajayram
5 Replies

9. Shell Programming and Scripting

How to run multiple functions in Background in UNIX Shell Scripting?

Hi, I am using ksh , i have requirement to run 4 functions in background , 4 functions call are available in a case that case is also in function, i need to execute 1st function it should run in background and return to case and next i will call 2nd function it should run in background and... (8 Replies)
Discussion started by: karthikram
8 Replies

10. Shell Programming and Scripting

How to log file processing details to database table usnig UNIX shell script?

we are getting files on daily basis.we need to process these files. i need a unix shell script where we can count 1-The no of files processed 2-No of data/record processed for each files. The script should log these details into a database table. If there is any error while file... (3 Replies)
Discussion started by: Atul kumar
3 Replies
CHSH(1) 							   User Commands							   CHSH(1)

NAME
chsh - change login shell SYNOPSIS
chsh [options] [LOGIN] DESCRIPTION
The chsh command changes the user login shell. This determines the name of the user's initial login command. A normal user may only change the login shell for her own account; the superuser may change the login shell for any account. OPTIONS
The options which apply to the chsh command are: -h, --help Display help message and exit. -R, --root CHROOT_DIR Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory. -s, --shell SHELL The name of the user's new login shell. Setting this field to blank causes the system to select the default login shell. If the -s option is not selected, chsh operates in an interactive fashion, prompting the user with the current login shell. Enter the new value to change the shell, or leave the line blank to use the current one. The current shell is displayed between a pair of [ ] marks. NOTE
The only restriction placed on the login shell is that the command name must be listed in /etc/shells, unless the invoker is the superuser, and then any value may be added. An account with a restricted login shell may not change her login shell. For this reason, placing /bin/rsh in /etc/shells is discouraged since accidentally changing to a restricted shell would prevent the user from ever changing her login shell back to its original value. FILES
/etc/passwd User account information. /etc/shells List of valid login shells. /etc/login.defs Shadow password suite configuration. SEE ALSO
chfn(1), login.defs(5), passwd(5). shadow-utils 4.5 01/25/2018 CHSH(1)
All times are GMT -4. The time now is 03:08 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy