sed command to replace slash with backslash

stelmed · 01-19-2004, 07:44 AM

Could someone provide me with the right command needed in order for sed to replace slash with backslash?
The default syntax "sed s/replace_this//with_this/g will work fine with letters but not with special charechters such as \ or /.

Than you in advance!

poison · 01-19-2004, 12:03 PM

did you try to escape those / and \ ?
like \/ for a slash and \\ for a backslash ?

magicm · 01-19-2004, 05:42 PM

poison has the key - however, the kicker is that this is very awkward to do straight from the command line because the shell will want to get in and parse the escape sequences in ways and times that will get in the way. However, if you store the sed commands in a file, it is quite simple.
For example, create a 1 line file namede "front2back.sed" containing

Code:

s/\//\\/g

then you can invoke sed like so:

Code:

sed -f front2back.sed < file2change.txt > newfile.txt

It will take all the forward slashes in file2change.txt, and make them back slashes in newfile.txt
Oh, - and see http://sed.sourceforge.net/sedfaq.html

stelmed · 01-20-2004, 10:05 AM

Really thank you guys!

baltho · 05-27-2008, 07:40 PM

Hi all,

I know, this is way too late but hopefully will help someone (like myself) who wants the command-line version to work instead.
I needed to double-backslash the contents of a file (SQL Insert statements, if you're wondering) in a command pipeline, looked here, kept on fiddling, and found that the simple solution is to use single rather than double quotes, which stops the shell from interpreting the contents of the sed command.

echo some-file.sql | sed -e 's/\\/\\\\/g' >some-other-file.sql

did the trick for me.

jong357 · 05-27-2008, 09:36 PM

Quote:

Originally Posted by baltho

the simple solution is to use single rather than double quotes, which stops the shell from interpreting the contents of the sed command.

You got it. That's the main reason for using double quotes.

Code:

[root@jaguar ~/Desktop] variable=blah
[root@jaguar ~/Desktop] echo $variable
blah
[root@jaguar ~/Desktop] echo $variable | sed 's/$variable/blek/'
blah
[root@jaguar ~/Desktop] echo $variable | sed "s/$variable/blek/"
blek

GazL · 05-28-2008, 05:26 AM

I know you asked specifically about sed, but with Unix, it's often better to ask "how to do x" rather than "how to do x using y", unless you specifically need to use 'y' that is. Quite often there are better alternatives.

For a simple replacement such as you describe 'tr' might suit you better and would possibly be more efficient to run.

Code:

tr '\' '/' <input.file >output.file

If you need to use sed because you're doing something more complex than that, then a little known tip is that you can actually use other delimiters to make it more readable. Though you still need to escape the '\' to stop sed misinterpreting it, you won't need to escape the '/'

I'm sure you'll agree that

Code:

sed -e 's:\\:/:g' input.file

is much clearer than

Code:

sed -e 's/\\/\//g' input.file

You've already had some answers so you've probably sorted this out, but I thought I'd share this anyway. Anyone who ever has to look at your code in future would thank you for using either of these techniques.

edit: oops, just noticed this was a revived thread. That'll teach me to look at the dates more closely. Ahh well, Maybe someone will find it useful if they stumble upon it.

GyulaCsom · 07-09-2010, 12:54 PM

I should tell that have found the tip on custom delimiters useful

That is when dealing with file path expressions in sed. For instance to dynamically remove an iSCSI LUN from ietd.conf one could simple put the following or kinda:

Code:

su -c "cat /etc/ietd.conf | sed -e \"s:Lun $LUN Path=$LUN_DEV,Type=blockio::g\" > /tmp/ietd.conf"
su -c "cp /tmp/ietd.conf /etc"

Without the custom delimiter the path expression '$LUN_DEV' would generate a sed error message...

tomaski2001 · 07-30-2010, 05:04 AM

is there a possibility to use a plugin to change file paths in mac into pc format? this means backslash has to change into fslash. I don't want to do it manually because it's about lot's of files veryday (work related).
Mainly i want to select a path (in file info) and copy it in a mail or a document with chanched slashes. Nobody finds a way.

Maybe here?

vst · 07-30-2010, 06:44 AM

tomaski2001,

have you actually tried sending windows users the paths with forward slashes? Thing is, forward slashes work in windows the same way, as backslashes do. Try it.

tomaski2001 · 07-30-2010, 07:10 AM

but it didn't work.
I also want to make it a hyperlink to a server location, but that also is not working.

GyulaCsom · 07-31-2010, 04:16 PM

Quote:

Originally Posted by tomaski2001

but it didn't work.

It should

That is Windows should honor file URLs, just as vst put. Try for instance the following sample urls:

Local file URL

Code:

file:///c:/tmp

If you put it into Windows Explorer it should open your local tmp folder.

Server file URL

Quote:

Originally Posted by tomaski2001

I also want to make it a hyperlink to a server location, but that also is not working.

Put something like this:

Code:

file://yourserver/sharedfolder

If you replace 'yourserver' and 'sharedfolder' with a server and folder you have access to windows explorer should open it.

More info
See Wikipedia for more details: File URI scheme

Hope it helps,

Cheers,
Gyula

Insulaner · 08-18-2010, 07:28 AM

i want to escape the dots of an url so i wrote the following code:

Code:

url="google.de"
echo $url	# output: google.de
escapedurl="`echo $url | sed 's:\.:\\\.:g'`"
echo $escapedurl	# output: google\.de
# content of /var/www/template :
# {url}
# {escapedurl}
sed "s:{url}:$url:g" /var/www/template | sed "s:{escapedurl}:$escapedurl:g"
# output:
# google.de
# google.de

the last output should be the escaped url but it doesn't work. the backslash is ignored. i guess it's a problem with the quotation marks. i also tried single quotes but then the variable is not interpreted.
so can anybody tell me how to fix this?

Insulaner · 08-19-2010, 05:01 AM

i got it, not enough backslashes:

Code:

escapedurl="`echo $url | sed 's:\.:\\\\\\\.:g'`"