How can find Null value in If condition


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting How can find Null value in If condition
# 1  
Old 07-17-2007
How can find Null value in If condition

Hi,
i wrote If Conditions in my script, it's returns null and some values.
but i am unable to find when Null value getting. bec we need modification according null vales.
pls help me on this.
# 2  
Old 07-17-2007
NULL strings would translate to a string of length zero.

You could do this to check for the NULL'ness of a string.

Code:
if [ ! -n "$VARIABLE" ] ; then
  echo "VARIABLE is empty"
fi ;

or

Code:
if [ -z "$VARIABLE" ] ; then
  echo "VARIABLE is empty"
fi ;

See man test to see the description of the flags -n and -z
# 3  
Old 07-17-2007
Code:
if [ "x $value" == "x """ ]
#if [ ! -n "$value" ]
then
        echo "empty"
else
        echo "Not empty"
fi

try it out..
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

To find record having null value

Hi All My requirement is to find the null values in particular column of a file and reject it in case if it contains null values. But the challenge is that I want a common command which can be used across different file, as the position of the column we need to check for different file may get... (14 Replies)
Discussion started by: ginrkf
14 Replies

2. Shell Programming and Scripting

How to find null column?

hi Gurus, I need find the null column in a file. my file like below abc, ,cde,def abc,ded,cdd,def abc, ,ddd,ccd aaa,bbb,ccc,ddd basic, I need to find the lines which second column is null Thanks in advance (3 Replies)
Discussion started by: ken6503
3 Replies

3. Shell Programming and Scripting

If condition to check null variable

Guys, Please help me on the below sample.cfg var=NULL sample.sh #!/bin/sh . /sample.cfg if ;then 1 st command here else 2 nd command here fi (3 Replies)
Discussion started by: AraR87
3 Replies

4. Shell Programming and Scripting

Checking for null condition in a UNIX variable

i have this code for i in `cat sql_output.txt` do -- some script commands done sql_output.txt has 1 column with employee_ids If the sql_output.txt is null then the do loop should not execute. How can i implement this. for i in `cat sql_output.txt` If i is null or empty then ... (5 Replies)
Discussion started by: rafa_fed2
5 Replies

5. Shell Programming and Scripting

Egrep ERE to find null

Hello All, My apologies if a similar question has already been posted. I searched for "grep", "egrep" and "null" I'm having an issue with egrep and an extended regular expression. I'm doing a test for a job name. I would like to have the user enter a job name with no spaces and also test to... (7 Replies)
Discussion started by: sydox
7 Replies

6. Shell Programming and Scripting

how to find null column

Hi, everyone I have a requirement as following: source file 1, abc, def, caaa 2, , cde, aaa 3, bcd, , adefefg I need find columns which contains null value, in above example, I need get two rows 2, , cde, aaa 3, bcd, , adefefg anybody has idea how to achive this ... (5 Replies)
Discussion started by: ken002
5 Replies

7. Shell Programming and Scripting

Find out if few fields in a file are null

Hi, I've a pipe delimited file where I want to find out a number of lines where 1st 2nd and last field are null using awk/sed. Is it possible? Thanks (5 Replies)
Discussion started by: rudoraj
5 Replies

8. UNIX for Dummies Questions & Answers

Using /dev/null with grep and find

Hi, I am trying to display the filename in which a string was found after using find and grep. For this after some googling I found that this works: find -name "*.java" -exec grep "searchStr" {} /dev/null \; I wanted to know the difference between the above and the following: find -name... (0 Replies)
Discussion started by: gaurav_s
0 Replies

9. UNIX for Dummies Questions & Answers

How to compare null and space using single if condition

Hi I have a input file with many fields and each filed will be with in double quotes(""). i want to check fields contains balnk,null or space using condition using if. when i write code as below for if condition its not working a=`awk -F ',' '{gsub("\"", "", $1);'NF==0';printf $1}'... (3 Replies)
Discussion started by: jayakumarrt
3 Replies

10. Shell Programming and Scripting

Find null fields in file

Hi All, I have some csv files out of which i want to find records which have empty values in either the 14th or 16th fields. The following is a sample. $cut -d',' -f14,16 SPS* | head -5 VOIP_ORIG_INFO,VOIP_DEST_INFO sip:445600709315@sip.com,sip:999@sip.com... (2 Replies)
Discussion started by: rahulrathod
2 Replies
Login or Register to Ask a Question