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Simple while-loop problem

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Top Forums Shell Programming and Scripting Simple while-loop problem
# 8  
Old 07-23-2010
Combining the various suggestions above:

Code:
#!/bin/bash
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=$((i + 1))
done

# 9  
Old 07-23-2010
Quote:
Originally Posted by methyl
Combining the various suggestions above:

Code:
#!/bin/bash
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=$((i + 1))
done

Nope, still not working, says syntax error at line 8: 'i=$' unexpected....if it helps to know im on Solaris..
# 10  
Old 07-23-2010
Quote:
Originally Posted by linuxkid
Nope, still not working, says syntax error at line 8: 'i=$' unexpected....if it helps to know im on Solaris..
If you have bash, it should work!

If this works, I suspect you're using sh:

Code:
i=`expr $i + 1`

Is
Code:
#!/bin/bash

the first line of your script?

what does
Code:
ls -l `which bash`

show?
# 11  
Old 07-23-2010
I suppose you're invoking the script in a way that the shebang is ignored and the script is executed by the old Bourne shell on Solaris.

You will need something like this in order to make it work with the old Bourne shell:

Code:
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=`expr $i + 1`
done

# 12  
Old 07-23-2010
If we haven't got bash, try ksh?

Code:
#!/bin/ksh
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=$((i + 1))
done



Or as suggested earlier do it in a way which works with Bourne Shell, ksh, bash and Posix shells.
Code:
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=`expr $i + 1`
done

# 13  
Old 07-23-2010
Quote:
Originally Posted by scottn
If you have bash, it should work!

If this works, I suspect you're using sh:

Code:
i=`expr $i + 1`

Is
Code:
#!/bin/bash

the first line of your script?

what does
Code:
ls -l `which bash`

show?
1) No
2)Yes
3) no such file or directory :s

---------- Post updated at 11:36 AM ---------- Previous update was at 11:35 AM ----------
Quote:
Originally Posted by radoulov
I suppose you're invoking the script in a way that the shebang is ignored and the script is executed by the old Bourne shell on Solaris.

You will need something like this in order to make it work with the old Bourne shell:

Code:
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=`expr $i + 1`
done

says unknown test operator $i

---------- Post updated at 11:37 AM ---------- Previous update was at 11:36 AM ----------
Quote:
Originally Posted by methyl
If we haven't got bash, try ksh?

Code:
#!/bin/ksh
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=$((i + 1))
done



Or as suggested earlier do it in a way which works with Bourne Shell, ksh, bash and Posix shells.
Code:
# Output the word "Hello" exactly 20 times
i=0
while [ $i -ne 20  ]
do
       echo "Hello"
       i=`expr $i + 1`
done


Smilie need i say more Smilie
# 14  
Old 07-23-2010
Quote:
Originally Posted by linuxkid
[...]

Smilie need i say more Smilie
Yes,
you need to post the exact content of the script (including the modified versions you're testing), the exact command you're executing and all the output/error messages that you're getting (copy/paste, please, don't try to re-write).

Enabling xtrace/verbose output would be beneficial also, hint: add this line to your script, after the first line:

Code:
set -xv

Last edited by radoulov; 07-23-2010 at 07:47 AM..
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