Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Checking if file exists using a NOT operator and shell variable
Top Forums Shell Programming and Scripting Checking if file exists using a NOT operator and shell variable Post 302304085 by rowlf on Saturday 4th of April 2009 08:06:05 PM
Old 04-04-2009
Checking if file exists using a NOT operator and shell variable
Hi,

I'm new to UNIX, at least shell programming and am having trouble figuring out a problem i'm having. In one section in my nested if statement, i want the program to test if the file does not exist, based on an argument supplied at the command line by the user. What i have is

PHP Code:
elif [ -e !$4 ]; then
              echo "Message: File \"$4\" does not exist. Creating new file."
              touch $4
              cp $2 $4
              set error=o 
and from there it goes down a long list of other conditions, but this is the only one giving me problems. It skips completely over it and doesnt print anything to screen.

Another problem i'm having is with error codes. I want certain error code values to display if the user should decide to ask for the error code level at the command line, using a logical AND in addition to the arguments supplied for the main part of hte program. I tried changing the last line in all of my nested ifs to

PHP Code:
set $?=<error code i wanted> 
bu that threw an error saying an assignment was attempted on a nonvariable. OK fine, so how would this be done? Is it even possible to set up specified error codes in a shell script that you can call by using 'echo $?' ?

Any help is appreciated, thanks !!


Using BASH shell btw.
Last edited by rowlf; 04-04-2009 at 09:30 PM..
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Checking the file if it exists

Hi This will be useful who is looking for checking the files in a directory #chmod 777 /cronacle/tools/teradata/opo/bin/file_check.sh SUBJECT=`echo "File Not Found"` SUBJECT1=`echo "File Found"` #RECIPIENT=Madhu.Reddy@ge.com cd /cronacle/tools/teradata/opo/bin file_list=attach.sh if ... (3 Replies)
Discussion started by: ksmbabu
3 Replies

2. Shell Programming and Scripting

Checking if a file exists

How can I check if a file exists in shell script. Basically, I want to check if a file Test_msgs has been created today. If it has been then append data to it. Otherwise, create it. I have written the following but it does not work. todaysdate=$(date +%d%m%Y) timenow=$(date +%H%M%S)... (4 Replies)
Discussion started by: gugs
4 Replies

3. UNIX for Dummies Questions & Answers

File already exists error while using '>' operator

hi i am using the below code grep -v '^$' file1.lst >file1.lst but it gives file1.lst already exists. And i want to over rite on the same file Whats the work around? (5 Replies)
Discussion started by: jathin12
5 Replies

4. Shell Programming and Scripting

Checking if file exists

How can I check if a file exists in csh? I know there is "-e $file" but do not know exactly how to use it. I have tried the below but I'm getting "Bad : modifier in $ ( )." foreach f ($AfullnameLst) if (-e $f) then echo "$f: file exists" endif end (6 Replies)
Discussion started by: kristinu
6 Replies

5. Shell Programming and Scripting

what is the difference between -f and -e, when checking for file exists

Hi All, what is the difference between -f and -e. Regards, ch33ry (1 Reply)
Discussion started by: ch33ry
1 Replies

6. Shell Programming and Scripting

Checking whether the file exists under a directory and doing a diff

Hi Everyone, I am writing a shell script for the below needs and would like your suggestions and advices. I have a lot of scripting files(Shell Scripts) under the directory: /home/risk_dev/dev I have another directory which has a lot of shell scripts under the directory: ... (2 Replies)
Discussion started by: filter
2 Replies

7. Shell Programming and Scripting

Checking if file exists and unzipping

Hey, I am new to scripting and was wondering what is wrong with this if statement. I want to check if file exists and the if it does to unzip it. I program it as follows if ; then gunzip *_filename.gz fi Thanks in advance! Please use code tags next time for your code and data. (10 Replies)
Discussion started by: mostarac2487
10 Replies

8. Shell Programming and Scripting

Determine a shell variable exists in file?

Hi Folks, Trying to build up a script that will lookup a username invoked as: ./buildscript.sh <username> This should take <username> and look it up in <username_file> and prepare for further processing. Here is the snippet that isn't working just right: user=$1 if ]; then echo... (1 Reply)
Discussion started by: gdenton
1 Replies

9. Shell Programming and Scripting

Problem with ssh and checking if file exists

Hi All, I am facing a problem while checking for existence of file over ssh ! Basically, i want to ssh and check if file exists.. If file exists return 1. If file does not exits return 0 (or any value) I am using the below code file_avail=`ssh username@host "if ]; then exit 1;... (10 Replies)
Discussion started by: galaxy_rocky
10 Replies

10. Shell Programming and Scripting

For loop without checking file exists

In several scripts that process files matched by name pattern I needed to add a check for file existence. Just to illustrate let's say I need to process all N??? files: /tmp$ touch N100 N101 /tmp$ l ?10 -rw-rw-r-- 1 moss group 0 Apr 19 11:22 N100 -rw-rw-r-- 1 moss group ... (10 Replies)
Discussion started by: migurus
10 Replies

LEARN ABOUT DEBIAN

php-config5

php-config(1)							Scripting Language						     php-config(1)

NAME

       php-config - get information about PHP configuration and compile options

SYNOPSIS

       php-config [options]

DESCRIPTION

       php-config is a simple shell script for obtaining information about installed PHP configuration.

OPTIONS

       --prefix       Directory prefix where PHP is installed, e.g. /usr/local
       --includes     List of -I options with all include files
       --ldflags      LD Flags which PHP was compiled with
       --libs	      Extra libraries which PHP was compiled with
       --man-dir      The directory prefix where the manpages is installed
       --extension-dir
		      Directory where extensions are searched by default
       --include-dir  Directory prefix where header files are installed by default
       --php-binary   Full path to php CLI or CGI binary
       --php-sapis    Show all SAPI modules installed on the Debian system
       --configure-options
		      Configure options to recreate configuration of current PHP installation
       --version      PHP version
       --vernum       PHP version as integer

       SEE ALSO
	      php(1)

VERSION INFORMATION

       This manpage describes php, version 5.4.4-14+deb7u14.

COPYRIGHT

       Copyright (C) 1997-2010 The PHP Group

       This  source  file  is  subject to version 3.01 of the PHP license, that is bundled with this package in the file LICENSE, and is available
       through the world-wide-web at the following url:
       http://www.php.net/license/3_01.txt

       If you did not receive a copy of the PHP license and  are  unable  to  obtain  it  through  the	world-wide-web,  please  send  a  note	to
       license@php.net so we can mail you a copy immediately.

The PHP Group							       2010							     php-config(1)
All times are GMT -4. The time now is 01:53 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy