topic Re: Variable assignment in Operating System - Linux

Variable assignment

Pavitra — Wed, 07 Feb 2007 01:18:43 GMT

How can i assign 2 values to a single variable??
for eg: if i have a variable named FILE and i want it to hold 2 filetypes so that in my further comparisons, FILE can take either of the 2 values.
Can anybody suggest???

Re: Variable assignment

Dennis Handly — Wed, 07 Feb 2007 01:23:31 GMT

You can have arrays with up to 1024 values. But you'll have to subscripts to check each value. Or use vector methods to check both at once (grep).

Of course you can always assign a string to a variable with a delimiter between them.

>i want it to hold 2 filetypes so that in my further comparisons, FILE can take either of the 2 values.

I'm not sure what you want here. Is there something in C that does what you want? You don't want enums do you?

Re: Variable assignment

Pavitra — Wed, 07 Feb 2007 01:37:45 GMT

Dennis,

will brief u on this.
i want FILE to hold 2 filetypes.
So that say.. if i want to put all the files with these filetypes somewhere else, i can directly use the variable FILE

Re: Variable assignment

Pavitra — Wed, 07 Feb 2007 01:40:15 GMT

And also,
Can anybody give me the syntax for multiple if`s inside awk??

Re: Variable assignment

Dennis Handly — Wed, 07 Feb 2007 02:07:18 GMT

>i want FILE to hold 2 filetypes.
So that say.. if i want to put all the files with these filetypes somewhere else, i can directly use the variable FILE

Well, you can concatenate all of the files in one variable (blank separators) and then use $FILE in commands like mv, etc.
FILE=$(ls *.c)

This will have the long string: a.c ... zzz.c

>Can anybody give me the syntax for multiple if's inside awk??

Same as C:
if (abc == def) {
...
} else {
...
}
You can add if-blocks after, or inside other ifs.

See awk(1).

Re: Variable assignment

Dennis Handly — Wed, 07 Feb 2007 02:48:24 GMT

Attached is a non-trivial awk program in C style.

Re: Variable assignment

Peter Nikitka — Wed, 07 Feb 2007 04:26:28 GMT

Hi,

a general handling of your request can be done by arrays.
In the following awk example we check, if the second field matches one of the values in 'str' AND when the line contains 'here-we-are'. Having this verified, we process this line later:

awk -v str='one two three' 'BEGIN {n=split(str,ary); found=0}
/here-we-are/ { for(i=1;i<=n;i++) if($2~ary[i]) {found=1;break} }
found { print "processing",$0 }'

mfG Peter