Subtracting an Integer from a Variable

The Observer · #1 (**permalink**) 06-10-2008

Hello,

I am in following situation.-

COUNT=`ls -l | wc -l`
echo $COUNT
---> 26
NO_OF_FILES=$COUNT-1
echo $NO_OF_FILES
---> 26-1

Here, I want the output to be 25. How could I do this. It seems simple, but I am not getting it. Please help me.

stcroix111 · #2 (**permalink**) 06-10-2008

use expr to do math.

NO_OF_FILES= expr $COUNT - 1

This should give you what you are looking for.

robotronic · #3 (**permalink**) 06-10-2008

If you only want a file count, you don't need to subtract anything. Just issue:

Code:

COUNT=`ls | wc -l`

If you want to compute calculations and you're using bash, try:

Code:

x=10
x=$((x-1))
echo $x

Otherwise, go with "expr" as said by stcroix111

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
Converting a String variable into Integer	neeto	UNIX for Dummies Questions & Answers	2	05-22-2008 03:38 PM
Subtracting date / timestamps	roadcyclist	Shell Programming and Scripting	0	06-21-2006 02:51 PM
Will we get SEGV if we try to “delete []” un-initialized integer pointer variable.	sureshreddi_ps	High Level Programming	2	10-11-2004 06:11 AM
capturing the output of grep as integer variable	babariba	UNIX for Dummies Questions & Answers	2	11-16-2001 10:42 AM
Subtracting Variables which are commands	Astudent	UNIX for Dummies Questions & Answers	2	03-30-2001 09:55 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by