Unix Scripting - Looping Query

[HHG]

Hi

Can anyone help please; I have created a simple script which transfers some files into another directory.

I need to put a whole loop around the main body.

Basically..
There will be a file which will hold a number of records.

e.g. number = 127

At the end of the script I need to reset the number to Zero in the file number.

Each time my script runs I want to check if this file has a zero init, if so I don't want it to process the next batch but instead wait. I want to do somthing like;-

if $a = 0
do
not do anything
else
do something.

Not sure which is the best loop to use for this. if, while etc. This is I think basic stuff, but not done scripting for a while. Anyone offer of help would be most appreciated.

Thanks

 

[feherke]

Hi

Not sure which is the best loop to use for this. if, while etc.

Well, [tt]if[/tt] is not a looping instruction, it is conditional.

Seems the best will be to make it with [tt]while[/tt].


Feherke.

http://rootshell.be/~feherke/

 

[MoreFeo]

Should work in ksh:

while [ ! $a = 0 ]
do
   do something
done

 

[HHG]

Thanks for this.

Can there be an else statement on this.

While
do
do somthing
else do
do something
done

If there is can you help with the syntax on this please. Thanks

 

[feherke]

Hi

At this point you should read some manual. Any manual about programming/scripting would be good.

No, usually you can not add [tt]else[/tt] clause to a [tt]while[/tt] statement. But of course, we can not affirm this firmly, while you still not revealed the name of your shell.

Use this as a starting point :

while :; do

  nr=`cat file_with_number`

  if [ "$nr" -eq 0 ]; then
    wait 10
  else
    # do what you want
  fi

done

Feherke.

http://rootshell.be/~feherke/

 

[HHG]

Thanks Feherke
I have a book infront of me so I managed to get the if else if bit. But the extra bit you have just sent me on while is good so I will use this. Thanks for your help.