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Full Discussion: sed doubt in extracting
Top Forums Shell Programming and Scripting sed doubt in extracting Post 302427846 by ripat on Tuesday 8th of June 2010 05:46:15 AM
Old 06-08-2010
Quote:
Originally Posted by royalibrahim
Hi,

Can anyone help me in understanding how the below code works?
Code:
echo "texxt" | sed 's/[^x]//'

gives output exxt, ideally it should give xxt. as this should remove the chars which is not x.
try
Code:
echo "texxt" | sed 's/[^x]//g'

Quote:
Originally Posted by royalibrahim
Code:
echo 'x_a_b_a_c_a_d' | sed 's/.*\(a\)/\1/'

gives output as a_d, which should be 'a' as it's the only character in the section
the output is normal. You ask to replace all characters up to *the last* a in string. Remember the sed regex are "greedy". They take all they can.

Quote:
Originally Posted by royalibrahim
Code:
echo 'foo-bar-1.4.5-19.spkg' | sed 's/-[^-]*$//'

and how the above code works?
Same as above. That pattern will take all non - characters following a - up to the end of the string. The only part of the string that match that pattern is from the last - up to the end.
 

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LEARN ABOUT DEBIAN

fixnt

fixnt(1)							      Debian								  fixnt(1)

NAME

       fixnt - Filter for the Windows NT postscript printer driver.

SYNOPSIS

       fixnt < BADFILE.ps > GOODFILE.ps

DESCRIPTION

       The  Windows  NT  postscript  driver has a tendency to make broken postscript files, that are incompatible with psutils.  fixnt is a filter
       that fixes these problems, allowing the use of psnup(1).

       The filter takes the broken postscript file on stdin, and outputs a fixed postscript file on stdout.  It has no other form  for	invocation
       and takes no options on the command-line.

OPTIONS

       fixnt  takes no options.

BUGS

       fixnt does not check for NTPSOct94.  For a workaround, use a sed(1) command to replace 'NTPSOct94' with 'NTPSOct95', like so:
	      sed 's/NTPSOct94/NTPSOct95/g'
       This is particularly important for Windows NT 3.5 users.

AUTHOR

       fixnt   was   written   by   Holger   Bauer   <Holger.Bauer@topmail.de>,  Michael  Rath	<rath@itsm.uni-stuttgart.de>,  and  Akim  Demaille
       <demaille@inf.enst.fr>.

REPORTING BUGS

       Report bugs to the Authors, but avoid sending large postscript files.

       Patches are always welcome; send to <bauer@itsm.uni-stuttgart.de>.

SEE ALSO

       psnup(1), sed(1)

a2ps								   February 2003							  fixnt(1)
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