How to write if loop in unix - UNIX for Dummies Questions & Answers

pinky · #1 07-25-2007

Hi Thanks to one who helped me to create a new thread
I am so new to unix and trying to learn the stuff
Thanks for all the help I am getting here
I wanted to execute if loop like

if( x=y || (x=z && x=q))
{
some statements
}

Can I get help how to do write the if loop in unix shell scripting
I know if it is for two like
if [[ x eq y || x eq z ]] but couldn't do it with the above requirement

Thanks in advance
PINKY

Shell_Life · #2 07-25-2007

Here is one form of looping:

Code:

#!/bin/ksh
typeset -i mCnt=0
while [ ${mCnt} -le 10 ]
do
  echo "Count = "${mCnt}
  mCnt=${mCnt}+1
done

DukeNuke2 · #3 07-25-2007

the syntax depends on the shell you are using...

in the korn shell an if statement looks like:

if [ $a = $b]
then
.....
else
.....
fi

pinky · #4 07-25-2007

Thanks for the answers
That didn't help me
I want if statement for exactly this condition
if(x=y || (y=z && a=b))

I was looking to write ksh script

Thanks again
Pinky

Shell_Life · #5 07-25-2007

Pinky,
Your 'if' statement is not clear on to what type the variables x,y,z,a,b are.

It makes a difference if they are string or numeric.

Numeric:

Code:

x=1
y=1
z=3
a=9
b=8
if [ $x -eq $y -o \( $y -eq $z -a $a -eq $b \) ]; then
 echo "FOUND NUMERIC"
else
 echo "NOT FOUND NUMERIC"
fi

Alphanumeric:

Code:

X='A'
Y='A'
Z='C'
A='M'
B='N'
if [ "$X" = "$Y" -o \( "$Y" = "$Z" -a "$A" = "$B" \) ]; then
 echo "FOUND CAPITAL ALPHA"
else
 echo "NOT FOUND CAPITAL ALPHA"
fi

pinky · #6 07-25-2007

Thanks I am sorry not to be clear that's for numeric
It worked perfect

Thanks for all your help

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