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Control characters in UNIX

 
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# 1  
Old 06-26-2014
Control characters in UNIX
Hi,

My files are showing some control characters in vi editor

^M
^@ and somtimes
^H

I removed ^M with %s/^M//g command
but how to represent ^@ and ^H
e.g. for ^M it is hold ctrl then v and m..

Please help..

I am very new to unix..
# 2  
Old 06-26-2014
Well the first thing you should ask yourself is the origin of the file: is it from a windows/DOS world, then it must be converted to remove the carriage return, either by a dos2ux or dos2unix command if it exist on your system that you hafve said nothing about or by writing a script to do the job.
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prabhat.diwaker
# 3  
Old 06-26-2014
I would expect ^M in Windows .txt files, but the ^H, ^@, and so forth are odd. Did these files come from the script utility?
This User Gave Thanks to Corona688 For This Post:
prabhat.diwaker
# 4  
Old 06-26-2014
ctrl+v is literal insert mode. ^ represents ctrl. so CTRL+V then CTRL+@ inserts the ^@ (which is a NUL byte)
This User Gave Thanks to neutronscott For This Post:
prabhat.diwaker
# 5  
Old 06-26-2014
we are running some scripts on the text files.. Scripts have been developed by dev team.. we are supposed to just run it and verify the output file.. after running the script on some set of files... output is having these characters.. anyhow dos2unix command is working.. thnks all Smilie

---------- Post updated at 10:24 PM ---------- Previous update was at 10:23 PM ----------

thnks neutronscott..

that too worked Smilie
# 6  
Old 06-26-2014
perhaps tr -d '[:cntrl:]' <oldfile >newfile to remove all control codes
This User Gave Thanks to neutronscott For This Post:
prabhat.diwaker
# 7  
Old 06-26-2014
Quote:
Originally Posted by neutronscott
perhaps tr -d '[:cntrl:]' <oldfile >newfile to remove all control codes
NO! Do not do this! That will remove all <newline> and <tab> characters as well as <backspace>, <carriage-return>, and other control characters that Prabhat might or might not want to remove.
 
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