check for NULL variable


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting check for NULL variable
# 1  
Old 03-19-2005
check for NULL variable

Hello

I want to check for NULL variable..

Quote:
val=
if [[-z "$val" ]]
then
echo NULL
fi

val=25
if [[ -z "$val" ]]
then
echo NOTNULL
fi
but this is not working..please help

thanks in advance
esham
# 2  
Old 03-19-2005
The first one is right if you put a space before the -z. For the second one switch to -n to test for non-null.
# 3  
Old 03-20-2005
that worked
Thanks a lot SmilieSmilieSmilie)

esham
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Check null values column

hi, I had a small question.I had a file from which i need to extract data. I have written the below script to check if the file exists and if it exists extract requierd columns from the file. IFILE=/home/home01/Report_1.csv OFILE=/home/home01/name.csv.out1 if #Checks if file exists... (1 Reply)
Discussion started by: Vivekit82
1 Replies

2. 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

3. Shell Programming and Scripting

Check null value in xml

Hi, I have a log file which is having some xml tags. I need to check the value for a particular xml field is null or not and if it is null i have to add current time as the value for that xml field. I tried below code to check whether the word count is 0. But even if the xml field is null it... (16 Replies)
Discussion started by: Neethu
16 Replies

4. Shell Programming and Scripting

Check for null

Hi Champs!!! im a newbie in unix, need ur expert help for my problem... I need to search if there are any "NULL" entries in the string String without Null Str1: 203652|1000003653|tellt|RUPV|4649|1|07/28/2011 01:56:12 String with Null (RUPV is removed) Str2:... (5 Replies)
Discussion started by: guruprasad7
5 Replies

5. Shell Programming and Scripting

check for null

hi, i have 3 lines of output , if second line exists then only condition within the if loop has to exeute other wise it has exit from loop. i had tried like this but not getting please help me ... Code: if ; then echo "success" else echo "" Use code tags please,... (8 Replies)
Discussion started by: sreelu
8 Replies

6. UNIX for Dummies Questions & Answers

Check for null values in a column

Hi All, I have a file with 10 columns and get the required data for nine columns properly except 8th. In 8th column i have both NULL and NON NULL values...i.e certain records have values for all the columns including 8th column and certain records have 8th column as NULL.My requisite is,without... (20 Replies)
Discussion started by: ganesh_248
20 Replies

7. Shell Programming and Scripting

How to check for null value from makefile

My makefile has some code as follows: if ; then \ echo copying tools; \ cp -f `../${TOOLS_ROOT_PATH}/ext_tools.sh 1` ${EXTERNAL_BIN_DIR} || exit $$?;\ fi; \ The ext_tools.sh is as follows: cat ttx.conf | grep external | grep -v ^# | awk '{print $1}' It can sometime result... (1 Reply)
Discussion started by: jake_ryan
1 Replies

8. Shell Programming and Scripting

how to check null variable

korn shell If then update_smartcare_user_password "$u_id" else echo "Not a database user" fi i get this error Syntax error at line *** : `then' is not expected. what should i do. I want to check whether $a is null or not. (2 Replies)
Discussion started by: sachin.gangadha
2 Replies

9. Shell Programming and Scripting

How to check for null or empty string

Hi, I need to check for value not equal (<>) to 21 and not equal empty or null values. Please modify this script if then echo "$VALUE,$BSC_NAME,$BSC_ID" > $OUT_FILE/power_up.out end if TQ (5 Replies)
Discussion started by: doer
5 Replies

10. Shell Programming and Scripting

check for not null string in file

Hi, If, in a text file a string is expected at a certain fixed position(for eg at position 5 or from 5-10 on every line) how to check whether data is present on that position or not? Thnx in advance (6 Replies)
Discussion started by: misenkiser
6 Replies
Login or Register to Ask a Question