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Help with sed

 
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# 1  
Old 04-28-2005
Question Help with sed
I am trying to use sed to delete lines of text within a source code file like java or c. I want to get rid of the comments so I want to get rid of things like // comments and /* comments */. I tried this command sed s'/[*//]//g' and it only gets rid of the "//" and some of the "/*" but none of the comments after them. I would please like some help on how I can do this. I am not even sure that I need to use sed but its what I think I need. Thanks.

Just in case if my question didnt make sense, heres an example:

Given this:
// comments ............
code
code
code
/* ............................
.................................
............................... */

I want only to delete the comments and none of the code so it would be:
code
code
code
# 2  
Old 04-28-2005
I found this at http://www.zazzybob.com/bin/remcoms.sed.html:

Code:
#!/usr/bin/sed -f
#< Remove C/C++ comments from files
# Another way to do it - adapted from a script found here
# http://sed.sourceforge.net/grabbag/scripts/remccoms1.sed
# to allow c++ // style comments to be removed
#
# c++ // comment removal code added KW 01/11/04
# comments added KW 02/11/04

# If pattern is not matched (i.e. line does not contain /*
# then branch to label :c
/\/\*/!bc

# Okay - line must contain /*, or we've branched here
# if line doesn't contain */ then append contents of next line to
# pattern space and continue - we must have got here by a branch
# to :a (or start of comment), so we can assume we're 
# processing a comment
:a
/\*\//!{
N
# branch back to :a to continue processing comment
ba
}
:c
# okay - not multiline comment - could be code, or single line
# comment

# replace single line comment with nothing
s:/\*.*\*/::

# replace // comment with nothing
s://.*$::g

Save it to a file called remcons.sed and use it like this:

sed -f remcons.sed yourfile

It seems to leave a blank line in the place of the comment.
# 3  
Old 04-28-2005
Thanks. I didnt know it would be complicated. I was wondering if it was possible to do it on the command line. It seems like a simple thing but I cant figure out an easy way to do it.
# 4  
Old 04-28-2005
Quote:
Originally Posted by SSteve

Save it to a file called remcons.sed and use it like this:

sed -f remcons.sed yourfile
You can also do:
./remcons.sed < yourfile

It is a script that is run by an interpreter called "sed".
# 5  
Old 04-28-2005
Quote:
Originally Posted by CSGUY
I didnt know it would be complicated.
The thing that makes it complicated is that /*...*/ can span more than one line. sed generally works on a single-line basis, so you have to do more advanced stuff like in the script I found.

Thanks, Perderabo, for the simplification. As you can tell, I'm still far from an expert.
 
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