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Full Discussion: Need Quick help on Understanding sed Regex
Top Forums Shell Programming and Scripting Need Quick help on Understanding sed Regex Post 302926430 by Scrutinizer on Monday 24th of November 2014 12:07:31 PM
Old 11-24-2014
It will remove trailing whitespace with a single space, but only if it is GNU sed. Regular sed does not understand \t, so then it will remove trailing spaces, backslashes and t's..

Regular sed
Code:
$ printf "%s\n" "Just wait      " | sed 's/[ \t]*$/ /'
Just wai

GNU sed:
Code:
$ printf "%s\n" "Just wait      " | sed 's/[ \t]*$/ /'
Just wait

Regular sed takes a hard TAB character (you can enter it with CTRL-V TAB)
Code:
printf "%s\t\t\n" "Just wait      " | sed 's/[       ]*$/ X/'
Just wait X

In the square brackets are a space and a TAB-character. This is also understood by GNU sed, so for portability use that instead of \t
Last edited by Scrutinizer; 11-24-2014 at 01:14 PM..
 

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LEARN ABOUT DEBIAN

nwbpset

NWBPSET(1)							      nwbpset								NWBPSET(1)

NAME

       nwbpset - Create a bindery property or set its value

SYNOPSIS

       nwbpset [ -h ] [ -S server ] [ -U user name ] [ -P password | -n ] [ -C ]

DESCRIPTION

       nwbpset Reads a property specification from the standard input and creates and sets the corresponding property. The format is determined by
       the output of 'nwbpvalues -c'. nwbpset will hopefully become an important part of the bindery management  suite	of  ncpfs,  together  with
       'nwbpvalues -c'. See util/nwbpsecurity for an example.

       As another example, look at the following command line:

	 nwbpvalues -t 1 -o supervisor -p user_defaults -c |
	 sed '2s/.*/ME/'|
	 sed '3s/.*/LOGIN_CONTROL/'|
	 nwbpset

       With  this command, the property user_defaults of the user object 'supervisor' is copied into the property login_control of the user object
       'me'.

	 nwbpvalues -t 1 -o me -p login_control -c |
	 sed '9s/.*/ff/'|
	 nwbpset

       This command disables the user object me.

       Feel free to contribute other examples!

       nwbpset looks up the file $HOME/.nwclient to find a file server, a user name and possibly a password. See nwclient(5) for more information.
       Please note that the access permissions of $HOME/.nwclient MUST be 600 for security reasons.

OPTIONS

       -h
	  -h is used to print out a short help text.

       -S server
	  server is the name of the server you want to use.

       -U user
	  user is the user name to use for login.

       -P password
	  password  is	the  password to use for login. If neither -n nor -P are given, and the user has no open connection to the server, nwbpset
	  prompts for a password.

       -n
	  -n should be given if no password is required for the login.

       -C
	  By default, passwords are converted to uppercase before they are sent to the server, because most servers require this. You can turn off
	  this conversion by -C.

AUTHORS

       nwbpset was written by Volker Lendecke. See the Changes file of ncpfs for other contributors.

nwbpset 							     8/7/1996								NWBPSET(1)
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