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If statement is not working in KSH

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# 8  
Old 02-09-2011
OMG ...It really funny now it's working just putting space after IF ... welcome to shell scripting .. Smilie
Code:
if  [-d /var/log/messages]
then
        echo "This dir not exists."
fi

Thanks much for helping me in this.
Last edited by Scott; 02-09-2011 at 11:07 AM.. Reason: Again, code tags please...
# 9  
Old 02-09-2011
Surely one space after the "if" and one space after the "[" and one space before the "]".

Code:
if [ -f /var/log/messages ]
then
        echo "This file exists"
fi

if [ -d /var/log ]
then
        echo "This directory exists
fi

if [ ! -d /var/log ]
then
        echo "This directory does not exist"
fi

# 10  
Old 02-09-2011
For me - only for ! or negative condition I should have to put space after IF,"[" and "]" but for normal or posivitive condtion only one space after if working. Anyway it good practice to put space as mentioned by you. Smilie
# 11  
Old 02-09-2011
It's not a question of "good practice". It's a question of correct syntax.

And to the shell, IF is not the same as if Smilie
# 12  
Old 02-09-2011
Quote:
Originally Posted by fpmurphy
It is also better practice to use:
Code:
if [[...]]

instead of:
Code:
if [...]


On the contrary: [ ... ] is standard and portable; [[ ... ]] is not.
# 13  
Old 02-09-2011
Quote:
Originally Posted by cfajohnson
On the contrary: [ ... ] is standard and portable; [[ ... ]] is not.
[[ ]] is necessary for glob-style matching comparison, and he specifically mentioned having ksh...

I find myself at a loss when it comes to testing code. Nobody ever made shells this terrible and old for Linux.
# 14  
Old 02-09-2011
Quote:
Originally Posted by Corona688
[..]I find myself at a loss when it comes to testing code. Nobody ever made shells this terrible and old for Linux.
How about dash which is the standard shell (/bin/sh) on Ubuntu ? It is not old but it does not support [[ ]]
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