regular expression

Ammad · 07-31-2008, 10:35 PM

Dear all,

Is it possible to replace "\" with "blank space" using sed.

thanks

pixellany · 07-31-2008, 11:22 PM

Quote:

Originally Posted by Ammad

Dear all,

Is it possible to replace "\" with "blank space" using sed.

thanks

Yes!!
.
Oh!!!--did you mean to ask HOW??

The trick here is that any character can be used as the separator in the SED "s" (substitute) construct. So, just use this general form:
sed 's#old#new#' (add a "g" to make it replace all "old" with "new".) old or new can now contain the "/".

The other method is to escape the "/" so that it is not interpreted as a separator. eg use "\/" to get a literal "/".

OOPS--I read "/" instead of "\"---see below.

Ammad · 08-01-2008, 12:23 AM

I used the following,

linux ~]# echo "this is\ test" | sed 's#\#windows#'
sed: -e expression #1, char 12: unterminated `s' command

linux ~]# echo "this is\ test" | sed 's#test#windows#'
this is\ windows

the first one outputs error, whereas if any other charcter it replaces successfuly.

ghostdog74 · 08-01-2008, 01:22 AM

You can use awk. make the input delimiter as "\" , then set output field delimiter as null

Code:

# echo "this is\ test" | awk -F'\' '{$1=$1;}1' OFS=""
this is test

minimal regular expression.

Kenhelm · 08-01-2008, 03:01 AM

In sed "\\" represents a literal "\"

Code:

echo "this is\ test" | sed 's/\\/windows/'
this iswindows test

pixellany · 08-01-2008, 07:41 AM

Sorry--I misread the original post.

Any character which normally has a special meaning has to be escaped. "/" only has special meaning in the "s" command when it is used as the delimiter. "\" is always special unless escaped.