question about define variable.

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01-26-2012

ken002

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question about define variable.

Hi, Unix Gurus,
In our existing file, there is a script like

Code:

#!/bin/sh
step=${1:-0}
cur_step=10
if [ $step -le $cur_step ]

...
My question is what's "${1:-0}" mean? I know it defines a variable but I don't know what's (1:-0) mean?

Thanks in advance.

ken002

01-26-2012

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If $1 isn't set, it becomes 0.

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01-26-2012

ken002

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Quote:

Originally Posted by Corona688

If $1 isn't set, it becomes 0.

Thanks for you quick reply.

ken002

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