sed replace end of line with character

grob115 · 02-13-2013, 05:01 AM

Hi, if I have a file with 10 lines, and all I want is to join the list of lines together in my file into a single line, by the characer '&', can someone explain why I need to do the following.

Code:

sed ':a;N;$!ba;s/\n/\&/g'

And can not with the following.

Code:

sed 's/\n/\&/g'

acid_kewpie · 02-13-2013, 05:44 AM

because sed is line based, to doesn't see the \n character, as that delimits the lines it processes.

tr would work easily though...

Code:

tr '\n' '&'

druuna · 02-13-2013, 05:45 AM

Quote:

Originally Posted by grob115

Hi, if I have a file with 10 lines, and all I want is to join the list of lines together in my file into a single line, by the characer '&', can someone explain why I need to do the following.

Code:

sed ':a;N;$!ba;s/\n/\&/g'

And can not with the following.

Code:

sed 's/\n/\&/g'

\n isn't part of the buffer (pattern space) when one line is stored, it is when multiple lines are stored in the buffer.

Have a look here: How to match newlines in sed

BTW: Wouldn't this be a better solution:

Code:

cat infile | tr '\n' '&'

grob115 · 02-13-2013, 01:44 PM

Ah damn. Thanks guys. Knew 'sed' is line based but got lost in within what I was trying to do.

danielbmartin · 02-13-2013, 03:01 PM

I like to use paste for this transformation.

InFile ...

Code:

albert
bernard
charles
david
edward
frank
george
henry
irving
john

Code ...

Code:

paste -sd\& $InFile > $OutFile

OutFile ...

Code:

albert&bernard&charles&david&edward&frank&george&henry&irving&john

Daniel B. Martin

grail · 02-14-2013, 09:18 AM

Code:

awk 'ORS="&"' file

danielbmartin · 02-14-2013, 10:03 AM

Quote:

Originally Posted by grail

Code:

awk 'ORS="&"' file

This awk produces a character string with a trailing ampersand. That's not exactly what the OP asked for.

Daniel B. Martin

danielbmartin · 02-14-2013, 10:16 AM

Quote:

Originally Posted by acid_kewpie

tr would work easily though...

Code:

tr '\n' '&'

This code ...

Code:

echo
echo; echo "Method of LQ Moderator acid_kewpie as posted"
echo; echo "InFile ..."; cat $InFile
tr '\n' '&' $InFile > $OutFile
echo "OutFile ..."; cat $OutFile

echo
echo; echo "Method of LQ Moderator acid_kewpie with <"
echo; echo "InFile ..."; cat $InFile
tr '\n' '&' < $InFile > $OutFile
echo "OutFile ..."; cat $OutFile

... produces this output ...

Code:

Method of LQ Moderator acid_kewpie as posted

InFile ...
albert
bernard
charles
david
edward
frank
george
henry
irving
john
tr: extra operand `/home/daniel/Desktop/LQfiles/dbm630inp.txt'
Try `tr --help' for more information.
OutFile ...


Method of LQ Moderator acid_kewpie with <

InFile ...
albert
bernard
charles
david
edward
frank
george
henry
irving
john
OutFile ...
albert&bernard&charles&david&edward&frank&george&henry&irving&john&

Why is it necessary to use the "<" to avoid the "extra operand" error message?

Daniel B. Martin

colucix · 02-14-2013, 10:22 AM

Quote:

Originally Posted by danielbmartin

Why is it necessary to use the "<" to avoid the "extra operand" error message?

Because tr doesn't accept a file name as argument: it works only on standard input.

danielbmartin · 02-14-2013, 10:28 AM

Quote:

Originally Posted by druuna

Have a look here: How to match newlines in sed

I clicked and got a pure gray screen; no text.

Daniel B. Martin

druuna · 02-14-2013, 11:33 AM

Quote:

Originally Posted by danielbmartin

I clicked and got a pure gray screen; no text.

Daniel B. Martin

Works on my side. Checked with Opera and disabled: cookies, plugins and javascript.

Just tried it with Firefox (Iceweasel) and it shows a grey screen....... Try manually adding index.php

grail · 02-14-2013, 12:03 PM

Quote:

This awk produces a character string with a trailing ampersand. That's not exactly what the OP asked for.

As does the tr solution, I picked up on the idea of replace all newlines with an ampersand as opposed to create a string with ampersand as the separator.

danielbmartin · 02-14-2013, 12:43 PM

Quote:

Originally Posted by druuna

Try manually adding index.php

This did the trick! Thank you.

Daniel B. Martin

mina86 · 02-14-2013, 05:52 PM

Code:

sed -n -e1h -e'2,$'H -e'$x' -e'$s/\n/\&/g' -e'$p'