Checking variables - Shell Programming and Scripting

penfold · #1 06-28-2005

Firstly - aplogies to Vino

I need to check wether or not a variable called DATE is actually a date by doing the following - checking it is all numeric and secondly checking if it is 8 digits long.

Any help appreciated

penfold · #2 06-28-2005

Just to clarify my previous post - is there any function within UNIX that would allow me to check if something is 8 digits long etc. apart from grep

vino · #3 06-28-2005

Quote:

Originally Posted by penfold

Firstly - aplogies to Vino

penfold,

No ill-feelings from my side. And I hope none from yours too.

Just letting you know on the rules that are followed in the forum.

Quote:

Originally Posted by penfold

I need to check wether or not a variable called DATE is actually a date by doing the following - checking it is all numeric and secondly checking if it is 8 digits long.

Any help appreciated

Code:

echo $DATE | sed -n -e '/^[0-9]\{8\}$/p'

If there exists $DATE and is an 8-digit number, it will print the contents of DATE.

Vino

penfold · #4 06-28-2005

#!/bin/sh

date1=01234567

echo $date1

echo $DATE | sed -n -e '/^[0-9]\{8\}$/p'

>> this produces the following

01234567
./check.sh: /: cannot execute
./check.sh: [0-9]{8}$/p: not found
sed: option requires an argument -- e

any ideas?

vino · #5 06-28-2005

You should echo $date1 to the sed command. Like this

Code:

#!/bin/sh

date1=01234567

echo $date1

echo $date1 | sed -n -e '/^[0-9]\{8\}$/p'

vino

penfold · #6 06-28-2005

This works great - thanks

What I need to do is to be able to echo 'DATE incorrect' if it is not 8 digits long or 'DATE correct' if it is..any ideas how to do this..

many thanks

vino · #7 06-28-2005

I am lost on how to use sed along with &&. Probably somneone could help me out.

So a grep solution.

Code:

 echo $DATE | grep -q '/^[0-9]\{8\}$/'  && echo "DATE correct" || echo "DATE incorrect"

Vino

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