shell script problem

i can't understand the if condition
this is an example but i can't understand what is th $1

$ cat > ispostive
#!/bin/sh
#
# Script to see whether argument is positive
#
if test $1 -gt 0
then
echo "$1 number is positive"
fi

plesae help me

thank you

The $1 variable refers to the first parameter passed to the script. The if statment just checks if the parameter given is greater than (-gt) 0.

BTW you may want to keep these sorts of questions in the 'newbie' or 'general' section. It is not relevant to networking.

thank you for your help

but stil i dont know where is the first parameter

thank you

i get it

but i have another question

what the diffrent between test statement and [ expr ] statement


thank you very much

The answer to all your questions can be found in the bash man pages.

Type: man bash

...at the first pause (bottom of screen -or- : ), type
/expr

from then on keep typing n (for next occurance)

Make sure you checkout the chapters labeled:
Positional Parameters
ARITHMETIC EVALUATION
CONDITIONAL EXPRESSIONS