expr command


 
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# 1  
Old 02-05-2010
expr command

Hi
Can anyone explain me the usage of this command and the arguments used here and what will be the expected output :

v_num=`expr nav_d_20100204_1759 : '[^(0-9)]*\([0-9]*\)'`

what will be the value returned in v_num.

Thanks in Advance!!!

Regards
Naveen Purbia
# 2  
Old 02-05-2010
Number matched by this pattern \([0-9]*\) is the output

Why dont you run the command and see the output?
# 3  
Old 02-05-2010
i run and got output as : 20100204 only.
why other numbers were ignored ?
# 4  
Old 02-05-2010
Change the pattern to
Code:
expr nav_d_20100204_1759 : '[^(0-9)]*\([0-9]*_[0-9]*\)'

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