Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Replace special characters with Escape characters?
Top Forums Shell Programming and Scripting Replace special characters with Escape characters? Post 302587613 by ctsgnb on Thursday 5th of January 2012 10:39:50 AM
Old 01-05-2012
@Laknar

Just for education purpose :

The trick is that in between a list [.....] some character have a special meaning :

The hyphen - is usually used to define and interval example : [0-9]

That is the reason why, in order to make it interpreted as litteral , it should be placed at a edge of the list (beginning or end) consider :
Code:
$ echo '!@#$%^&*()-' | sed 's/[-!@#$%^&*()]/\\&/g'
\!\@\#\$\%\^\&\*\(\)\-
$ echo '!@#$%^&*()-' | sed 's/[!@#$%^&*()-]/\\&/g'
\!\@\#\$\%\^\&\*\(\)\-

There is another special case within a list [......] :
The closing square bracket ]
This special closing square bracket - to be taken as litteral (so that the substitution will apply)- needs to be setup at the very first position in the list otherwise it is take as end of the list or unexpected behaviour may occure.

Consider the following example :
Code:
$ echo '!@#[]$%^&*()-' | sed 's/[]!@#[$%^&*()-]/\\&/g'
\!\@\#\[\]\$\%\^\&\*\(\)\-
$ echo '!@#[]$%^&*()-' | sed 's/[-!@#[$%^&*()]]/\\&/g'
!@#\[]$%^&*()-
$ echo '!@#[]$%^&*()-' | sed 's/[-!@#[]$%^&*()]/\\&/g'
!@#[]$%^&*()-

Last edited by ctsgnb; 01-05-2012 at 12:57 PM..
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Need help to escape special characters in Korn shell script

Hi, I would like to display the following message from my shell (Korn) script Copy "old_file.txt" to "new_file.txt" My code looks as follows print "Copy "old_file.txt" to "new_file.txt"" However, when I execute the script, I get the following output Copy old_file.txt to... (6 Replies)
Discussion started by: rogers42
6 Replies

2. Shell Programming and Scripting

awk print $1 escape all special characters

I'm using awk '{print $1}' and it works most of the time to print the contents of a mysql query loop, but occationally I get a field with some special character in it, is there a way to tell awk to ignore all special characters between my FS? I have >186K records, so building a list of ALL special... (6 Replies)
Discussion started by: unclecameron
6 Replies

3. Shell Programming and Scripting

Replace new line with <br /> & escape special characters

Hi, I wish to replace a new line with br (html) but it doesn't seem to work message=$(echo ${FORM_message} | tr '\r' '<br \/>' ) what it gives me seems to be ... b...? I am also having problem escaping hash sign in cut command: list=$(echo "$line" | cut -d'\#;\#' -f1) ; my intention is... (2 Replies)
Discussion started by: ted_chou12
2 Replies

4. Solaris

How to replace special characters in vi?

Hi , I want to replace the special characters in the file. For eg: cat abc 1234/4455/acb 234/k/lll/ 234`fs`fd I want to replace / and ` with the letter a and the output should like below. How to achieve this. 1234a4455aacb 234akallla 234afsafd (2 Replies)
Discussion started by: rogerben
2 Replies

5. Shell Programming and Scripting

Need help with sed to escape special characters

Hello Everyone, I need to read an encrypted password from the user and update that value in an xml file. I am trying to use "sed" for searching the appropriate tag and replacing this new value that get from the user. Since the encrypted password can contain special characters(like /,\,&,etc),... (4 Replies)
Discussion started by: majose
4 Replies

6. Shell Programming and Scripting

Escape special characters in SED

Need help in escaping special characters in sed command. Here is the the string which i am trying to find a replace with From :- REQUEST_TYPE=PIXEL&amp;MSG_ID={//MESSAGE_ID} To :- REQUEST_TYPE=PIXEL&amp;MSG_ID= X_EDELIVERY_MESSAGE_ID &amp; BATCH_ID= X_EDELIVERY_BATCH_ID Here is the sed command i am... (2 Replies)
Discussion started by: aakishore
2 Replies

7. Shell Programming and Scripting

How to replace special characters?

Hi Unix Guru, I have an requirement for replace some specail characters in a file, my file came from mainframe. please see below example: when open it with vi 17896660|89059215|04/24/1998 00:00:00.000000| abc 123-453-1312^M<85>^M<85>|124557 if I run cat -v I got following:... (25 Replies)
Discussion started by: ken002
25 Replies

8. Shell Programming and Scripting

How to escape Special Characters in Expect programming?

Hi, I have written a unix expect utility "ssh-login.exp" which connects (ssh) to remote host and execute some shell script. I am calling this "ssh-login.exp" utility from another shell script. "ssh-login.exp" takes username, password, host and shell script path to execute on remote host. All... (1 Reply)
Discussion started by: Mahesh Desai
1 Replies

9. Shell Programming and Scripting

How to escape all special characters?

I have an application which I am integrating with that accepts the password via a CLI. I am running in to issues with passwords that contain special characters. I tried to escape them all, but I ran in to an issue where I cannot escape the characters ' ] My attempt is as follows: $... (2 Replies)
Discussion started by: AMG1978
2 Replies

10. UNIX for Advanced & Expert Users

How to replace special characters?

Hi Team, I have data like this. |*|.5|*|0.2|*|A.B|*| Would like to add zero (0) before the decimal point where there is no zero as |*|0.5|*|0.2|*|A.B|*| How to replace |*|. with |*|0. I tried below command which didn't work echo '|*|.5|*|0.2|*|A.B|*' | sed... (4 Replies)
Discussion started by: Ravi.K
4 Replies

LEARN ABOUT CENTOS

grub-render-label

GRUB-RENDER-LABEL(1)                                               User Commands                                              GRUB-RENDER-LABEL(1)

NAME

       grub-render-label - generate a .disk_label for Apple Macs.

SYNOPSIS

       grub-render-label [OPTION...] [OPTIONS]

DESCRIPTION

       Render Apple .disk_label.

       -b, --bgcolor=COLOR
              use COLOR for background

       -c, --color=COLOR
              use COLOR for text

       -f, --font=FILE
              use FILE as font (PF2).

       -i, --input=FILE
              read text from FILE.

       -o, --output=FILE
              set output filename. Default is STDOUT

       -t, --text=STRING
              set the label to render

       -v, --verbose
              print verbose messages.

       -?, --help
              give this help list

       --usage
              give a short usage message

       -V, --version
              print program version

       Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

REPORTING BUGS

       Report bugs to <bug-grub@gnu.org>.

SEE ALSO

       The  full  documentation  for grub-render-label is maintained as a Texinfo manual.  If the info and grub-render-label programs are properly
       installed at your site, the command

              info grub-render-label

       should give you access to the complete manual.

grub-render-label (GRUB) 2.02-2ubuntu8.3                             July 2018                                                GRUB-RENDER-LABEL(1)
All times are GMT -4. The time now is 03:37 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy