if loop problem in bourne shell

ahmad.diab · #1 (**permalink**) 09-18-2008

how to use if-loop in bourne shell with multiple conditions like follows

if [ a > b && c > d ]
then
commands
fi

it gives me an error

test: ] missing

then i put
if [[ a > b && c > d ]]
it gives me an error
[[ not found

kindly i need the syntex for the bourne shell

avronius · #2 (**permalink**) 09-18-2008

Have you tried

Code:

if [ a > b ] && [ c > d ]

jim mcnamara · #3 (**permalink**) 09-18-2008

You must have an ancient version -

Code:

if [ $a -gt $b ] ; then
   if [ $c -gt $d ] ; then
   fi
fi

is what you will have to use.

joeyg · #4 (**permalink**) 09-18-2008

The first example executes to TRUE, and prints "greater". The second example is FALSE, and nothing prints

Code:

> if [ 14 -gt 13  -a  15 -gt 12 ] ; then echo "greater"; fi
greater

> if [ 4 -gt 13  -a  5 -gt 12 ] ; then echo "greater"; fi

avronius · #5 (**permalink**) 09-18-2008

Quote:

You must have an ancient version -

Seems I wasn't paying attention to the argument - just the format! Thanks Jim

This is what it could look like:

Code:

if [ $a -gt $b ] && [ $c -gt $d ]

ahmad.diab · #6 (**permalink**) 09-20-2008

Thanks a lot guys , all the syntax worked fine except this one

if [ a > b ] && [ c > d ]

...thanks again

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