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Top Forums Shell Programming and Scripting Handling null Integer/string variables Post 302604749 by lan123 on Monday 5th of March 2012 11:38:25 PM
Old 03-06-2012
Hi guys, thanks a lot for so many replies....

It was good solution to use
Code:
ps -ef | grep "[m]intty" | awk '{print $2}'

This works and gives only one PID. The actual problem I found out was that, the variable never gets a value assigned. The PID value getting printed was from the following step.
Code:
LAN_VARIABLE= echo `ps -ef | grep "[m]intty" | awk '{print $2}'`

echo $LAN_VARIABLE always returned null, hence the if loop had the ambiguity.


I used the following and it worked.
Code:
if [-z `ps -ef | grep [m]intty | awk '{print $2}'`]; then
echo "not an Integer"
else
echo "An Integer"
fi


Last edited by Franklin52; 03-06-2012 at 03:09 AM.. Reason: Please use code tags for code and data samples, thank you
 

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index(3C)						   Standard C Library Functions 						 index(3C)

NAME
index, rindex - string operations SYNOPSIS
#include <strings.h> char *index(const char *s, int c); char *rindex(const char *s, int c); DESCRIPTION
The index() and rindex() functions operate on null-terminated strings. The index() function returns a pointer to the first occurrence of character c in string s. The rindex() function returns a pointer to the last occurrence of character c in string s. Both index() and rindex() return a null pointer if c does not occur in the string. The null character terminating a string is considered to be part of the string. USAGE
On most modern computer systems, you can not use a null pointer to indicate a null string. A null pointer is an error and results in an abort of the program. If you wish to indicate a null string, you must use a pointer that points to an explicit null string. On some machines and with some implementations of the C programming language, a null pointer, if dereferenced, would yield a null string. Though often used, this practice is not always portable. Programmers using a null pointer to represent an empty string should be aware of this portability issue. Even on machines where dereferencing a null pointer does not cause an abort of the program, it does not necessarily yield a null string. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ |ATTRIBUTE TYPE |ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
bstring(3C), malloc(3C), string(3C), attributes(5), standards(5) SunOS 5.11 24 Jul 2002 index(3C)
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