how to use expr

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Operating Systems Linux Red Hat how to use expr
# 1  
Old 11-30-2007
Java how to use expr

i am new to shell programming, currently using redhat linux of version
i have problem in executing expr command in the following shell script

$ x=5
$ x='expr $x + 1'
$ echo $x

the output is displaying always
expr $x + 1

Pls guide me for the above query
# 2  
Old 11-30-2007
how to use expr

You need to use back tics not single quotes

x=`expr $x + 1`
# 3  
Old 01-05-2009
I tried to use expr for multiplication, but got an error. I used '*' symbol. Can you tell me what's the problem, or if there is another way? Thanks
# 4  
Old 01-05-2009
escape the * it is a shell metacharacter
a=$( expr 13 \* 3)
# or
a=`expr 13 \* 3`

This User Gave Thanks to jim mcnamara For This Post:
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