Incrementing a variable is not happening


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Incrementing a variable is not happening
# 1  
Old 11-28-2008
Question Incrementing a variable is not happening

Hi All,

Iam trying to increment a variable

Following is the code

#!/usr/bin/ksh
i=1;
i='expr $i+1';
echo $i;

Output:
expr $i+1

not able to understand why its happening in that way

i was expecting result as 2... if the above method is worng .. can you help how i can get that

Last edited by kiranlalka; 11-28-2008 at 11:05 AM..
# 2  
Old 11-28-2008
Needs backticks not quotes. Also, lose the semicolons.

Quote:
#!/usr/bin/ksh
i=1
i=`expr $i + 1`
echo $i
# 3  
Old 11-28-2008
Computer

Quote:
Originally Posted by methyl
Needs backticks not quotes. Also, lose the semicolons.
Thanks Methyl.. It worked... BTW, Iam new to shell scripting
# 4  
Old 11-28-2008
Quote:
Originally Posted by kiranlalka
Hi All,

Iam trying to increment a variable

Following is the code

Please put code inside [code] tags.
Quote:
Code:
#!/usr/bin/ksh
i=1;
i='expr $i+1';


With a POSIX shell, such as ksh or bash, you don't need to use an external command (such as expr) to do integer arithmetic:

Code:
i=$(( $i + 1 ))

Login or Register to Ask a Question

Previous Thread | Next Thread

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Passing specific and incrementing lines of text from file via variable

This is part of a larger script where I need to pass only 1 line of a file to the script, based on a variable and not a direct reference. As part of a for loop : # for((line=0;line<50;line++)); do # awk ‘NR==$line' PhraseList.txt; done ... (5 Replies)
Discussion started by: Seth
5 Replies

2. Fedora

Leap second happening

Have anybody heard about the Leap second problem Leap second :A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time. How could i avoid such thing in my script which i deal with... (6 Replies)
Discussion started by: wnaguib
6 Replies

3. Shell Programming and Scripting

incrementing the variable name along with the data?

Hello folks. I am trying to increment my variable names to match a counter that is to be used later on... Basically, i have a for loop that lists directories (for example TEST_OS DVP_OS PROD_OS ) but this loop is not static, it may contain 3 directory once and the next run 5 directories. I... (6 Replies)
Discussion started by: Stephan
6 Replies

4. UNIX for Dummies Questions & Answers

Incrementing variable in for

Hi, want to increment a variable in a for loop like this: for (( c=$total-1; c>=0; c-- )) do if ; then maximo=$valores fi done But it gives the error: No such file or directory How can i do this only incrementing the c variable? Thanks (8 Replies)
Discussion started by: limadario
8 Replies

5. UNIX for Dummies Questions & Answers

Incrementing Variable Names

Hi, I am using BASH. I have encountered a situation where the following is necessary (but I am not sure how to do it): #Define multiple arrays, whose names only differ by a number: ARRAY_1=(1 2 3) ARRAY_2=(4 5 6) ARRAY_3=(7 8 9) #Define ARRAY_AMOUNT, the number of arrays. In this case... (1 Reply)
Discussion started by: msb65
1 Replies

6. Shell Programming and Scripting

Facing problem in incrementing the variable

When I did, echo $SHELL in cmd prompt of putty, its displaying /bin/sh And in my shell script., I hav started with., #!/bin/sh and i=1; while ; do . . . i=$; (9 Replies)
Discussion started by: av_vinay
9 Replies

7. Homework & Coursework Questions

Incrementing Variable resets outside of while loop

1. The problem statement, all variables and given/known data: Variable is resetting to 0 after incrementing in while loop My bit of scripting displays the current users logged in the machine. Then it reads in a specific username and displays the processes for that user. The portion that I... (3 Replies)
Discussion started by: ratzlaff
3 Replies

8. Linux

Incrementing the date stored in the variable

Hi all, I have a variable with date as 20080831 . Now I want to increment it as 20080901 and so on.Is there any command for this. Please help me. thanks rameez (1 Reply)
Discussion started by: rameezrajas
1 Replies

9. AIX

Ping is happening, telnet is not happening

HI all, Ping is happening to a AIX box...but telnet is not happening... AIX box doesn't have any conslole... Please help how to resolve it. Thanks in advance .. Manu (2 Replies)
Discussion started by: b_manu78
2 Replies
Login or Register to Ask a Question