Control character in a file

cursive · #1 (**permalink**) 04-25-2007

Hi All,

I am looking for a solution to capture any ASCII control character in a file
( where the ASCII control character is in decimal value from 0 to 31 and 127
( Hex value from 00 to 1F and 7F ) ) by returning any affected lines.

The intended good file should contain "ASCII printable character" where ASCII
printable character is in decimal value from 32 to 126 ( Hex value from 20 to
7E ).

Thanks in advance.

Best regards,
cursive

anbu23 · #2 (**permalink**) 04-25-2007

Removes ASCII control characters from 0 to 31 and 127

Code:

tr -d "\000-\037\177" < file

Code:

while read line 
do
       [[ -n "$( echo $line | tr -d "\000-\037\177" )" ]] && echo "$line"
done < file

ghostdog74 · #3 (**permalink**) 04-25-2007

you may also want to try awk's POSIX character classes like [:print:],[:graph:] etc...

cursive · #4 (**permalink**) 04-25-2007

Hi Anbu23,

I am not sure if I missing something here by using the given solution :
tr -d "\000-\037\177" < file because the output is still contained the control
character.

Provided a sample of the input file :
-------------------------------------------------
Monday Tuesday Wednesday
Thursday Friday
Saturday
Sunday
Number = 0.36")· )

Apple orange
Pinapple

Output file ( display lines with control character ):
---------------
>Monday Tuesday Wednesday
>Saturday
>Number = 0.36")· )
>Apple orange
>

Thanks in advance,
cursive

anbu23 · #5 (**permalink**) 04-25-2007

Code:

/db2home/training$ cat -e f
Monday Tuesday Wednesday$
Thursday Friday$
Saturday ^F$
Sunday$
Number = 0.36")· )$
$
Apple orange $
Pinapple$
^G$
/db2home/training$ tr -d "\000-\011\013-\037\177-\377" < f | cat -e
Monday Tuesday Wednesday$
Thursday Friday$
Saturday $
Sunday$
Number = 0.36") )$
$
Apple orange $
Pinapple$
$

cursive · #6 (**permalink**) 04-26-2007

Hi anbu23,

Thanks for the solution and it work perfectly.

Best regards,
cursive

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
Can I read a file character by character?	murtaza	Shell Programming and Scripting	4	04-27-2009 05:51 AM
Can i read a file character by character	karnan	Shell Programming and Scripting	6	05-19-2008 02:22 AM
create control file in UNIX	alfredo123	UNIX for Dummies Questions & Answers	5	06-06-2006 11:24 AM
Disable printing control file	cpuhl	UNIX for Advanced & Expert Users	1	06-01-2005 04:19 PM
Control saving file by type	saswerks	UNIX for Dummies Questions & Answers	4	02-15-2005 04:47 PM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: