sed converting / to \/ - UNIX for Advanced & Expert Users

sakthi.abdullah · #1 (**permalink**) 12-12-2006

Hi all,
I am using sed for converting a string of type /abc/def/gh by \/abc\/def\/gh

[trainee@LINUX ~]$ edu="/home/abc/dec"

When I echo that variable and pass it to sed ,it works fine...
[trainee@LINUX ~]$ echo $edu|sed 's/\//\\\//g'
\/home\/abc\/dec

But When I try to store in a variable , it shows the following error

[trainee@LINUX ~]$ ued=`echo $edu|sed 's/\//\\\//g'`
sed: -e expression #1, char 9: unknown option to `s'

HELP BLEAZ

jim mcnamara · #2 (**permalink**) 12-12-2006

Code:

echo "a/b/d" | sed 's#/#\\/#g'

When you are using sed to work with "/" characters you have to use another delimiter - in this case I picked "#"

sakthi.abdullah · #3 (**permalink**) 12-12-2006

Can you explain this further because
Usually it's of the form s/old/new/g but sed 's#/#\\/#g' contains only s/.../g

sakthi.abdullah · #4 (**permalink**) 12-12-2006

Quote:

Originally Posted by jim mcnamara

Code:

echo "a/b/d" | sed 's#/#\\/#g'

When you are using sed to work with "/" characters you have to use another delimiter - in this case I picked "#"

Again, echo "a/b/d" | sed 's#/#\\/#g' ll work fine.... But What I need is something like this ..how can I store that value on to a variable
like abc=`echo "a/b/d" | sed 's#/#\\/#g'`

vino · #5 (**permalink**) 12-12-2006

Quote:

Originally Posted by sakthi.abdullah

abc=`echo "a/b/d" | sed 's#/#\\/#g'`

Turn the backticks into $(...). See this.

Code:

[~]$ abc=`echo "a/b/d" | sed 's#/#\\/#g'`
[~]$ echo $abc
a/b/d
[~]$ abc=$(echo "a/b/d" | sed 's#/#\\/#g')
[~]$ echo $abc
a\/b\/d
[~]$

Hmm.. I am a little surprised with the difference in behaviour of `...` and $(...)

Edit
Ah ! Here's how it goes with the backticks.

Code:

[/tmp]$ abc=`echo "a/b/d" | sed 's#/#\\\\/#g'`
[/tmp]$ echo $abc
a\/b\/d

And here's why. From man sh

Code:

       When  the  old-style  backquote  form of substitution is used, backslash
       retains its literal meaning except when followed by $,  ?,  or  \.   The
       first  backquote not preceded by a backslash terminates the command sub-
       stitution.  When using the $(command) form, all characters  between  the
       parentheses make up the command; none are treated specially.

/Edit

Perderabo · #6 (**permalink**) 12-12-2006

Backtick version:
abc=`echo "a/b/d" | sed 's#/#\\\\/#g'`

but I strongly prefer $(...) to `...` for many reasons.

sakthi.abdullah · #7 (**permalink**) 12-13-2006

Quote:

Originally Posted by Perderabo

Backtick version:
abc=`echo "a/b/d" | sed 's#/#\\\\/#g'`

but I strongly prefer $(...) to `...` for many reasons.

Can you please mention those ..

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
converting hex to dec	aismann	Shell Programming and Scripting	4	02-26-2008 01:51 AM
Converting \0 to a \n	ajcannon	Shell Programming and Scripting	2	09-28-2007 08:30 AM
Converting	seeyou	SCO	3	01-19-2006 10:22 AM
converting .txt	laila63	UNIX for Dummies Questions & Answers	4	06-30-2004 01:56 PM
converting kb to mb	csaunders	UNIX for Dummies Questions & Answers	1	02-26-2004 12:14 PM

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode