string test?

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# 8  
Old 03-29-2002
awk substr examples??

Thanks for the feedback. I searched the man pages but I don't see any good examples for substr usage with awk. Do you have any examples out there that you can share?
# 9  
Old 03-29-2002

I posted my question before I realized that I now had an example. Thanks for your help guys..!
# 10  
Old 03-29-2002
awk substr is just for pulling part of a string, and is not used for string testing, although the operands of substr, such as starting position and length, can involve string testing. For example, the substr operand for starting position could be an index function for locating a desired starting position using a pattern match.

Following is an example using awk to test for six digits. Unlike the expr command, which has an assumed beginning-of-line anchor, this pattern has to be anchored at the front. The ! means NOT, so if the input is not exactly six digits, it will exit with code 1, else code 0.
echo $myvar |
awk '!/^[0-9]{6,6}$/ {exit 1}'

if [ $? = 0 ] ; then
   echo 'six digits'
   echo 'NOT six digits'

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