UNIX for Dummies Questions & Answers

Thanks Perderabo...

I am using AIX, version 4.

I want to keep the special characters like double quotes("), spaces, +, - etc. retained. When I used :
tr -c '[:print:][:cntrl:]' ' ' < input_file > output_file

all these characters also got removed. (Anything to do with [:print:] ?)


Also, [:alnum:] didn't change the file itself :

tr -c '[:alnum:]' ' ' < subs.bak > sub.err


Have got tired of using so many options. Have to resolve this issue as soon as possible. Clients jumping on me.

Thanks
Kanu

Are there some more options? Thanks in advance..
-Kanu

If the list of characters to be removed is finite have them in the file "unwanted_chars"

and try this code

Code:

#! /opt/third-party/bin/perl

open(FILE, "<", "unwanted_chars");

while(<FILE>) {
  chomp;
  $fileHash{$_} = 0;
}

close(FILE);

open(FILE, "<", $ARGV[0]) || die ("unable to open <$!>\n");

while( read(FILE, $data, 1) == 1 ) {
  $ordVal = ord($data);
  print $data if( !defined($fileHash{$ordVal}) );
}

close(FILE);

exit 0

But if you are sure only ASCII characters need to be in the data file then its much more simpler, range can be specified and no need to use an external lookup file

Thanks Madhan! The list of characters is not finite. These are some dump character which creep into the records. I believe it would be helpful if you see my attached example.

Anyways, the logic is good. Atleast I can remove some of the characters which I know.

Thanks
Kanu

I doubt that. Could you please double - check what is the encoding character that is set as default and what is the encoding character set of the input file ?

Actually these are valid characters but not for all the character sets.

It might be that they are valid and due to the encoding character set of the terminal it might turn out to be junk or unwanted characters.

Better take a hex dump of the file and verify its needed or not

I dont know why, but I always wanted to get this answer.
I always doubted this. I think at the place of 'space' some dump characters are coming.
How can I check the encoding character set of the terminal?
Can I change it too?
I want to resolve the root cause, so that we can avoid using some more scripts.

Thanks
Kanu

This is what I got :

#echo $LANG
En_US

Helpful?