sed help needed

ZAMO · 01-09-2009, 05:29 AM

Hi all,

Am on the way of learning sed using Bash-Beginners-Guide.pdf. Suddenly i got questions myself of how to print the lines , say 5-10 in a file using sed.

1.How to print a line ,say 28 only in a file using sed?
2.How to print from line 5-10 in a file ?
3.How can list all my files in my home directory using sed?

Can someone suggest me a dedicated document(pdf pref) for "sed"

Thanks

billymayday · 01-09-2009, 05:33 AM

Here's a really good sed tutorial for you

http://www.ibm.com/developerworks/li...ry/l-sed1.html

Why would you use sed to list files in your home directory?

colucix · 01-09-2009, 05:37 AM

Here is another really good sed tutorial:

http://www.grymoire.com/Unix/Sed.html

ZAMO · 01-09-2009, 05:38 AM

Code:

Why would you use sed to list files in your home directory?

It is there in the Exercise part of the pdf and it is interesting to know , sed to list the files in a directory.

jschiwal · 01-09-2009, 06:17 AM

You might use sed to reformat the list of files in your home directory, but the list will be supplied either by file globbing or ls or find.

If you move on to learning awk as well, I would recommend downloading the source package for 'gawk' and using "make pdf" to produce the "GAWK: Effective Awk Programming".

The "Sed & Awk" O'Reilly book is very good. The first edition might be available as a pdf on the web.

colucix · 01-09-2009, 06:34 AM

Quote:

Originally Posted by jschiwal

If you move on to learning awk as well, I would recommend downloading the source package for 'gawk' and using "make pdf" to produce the "GAWK: Effective Awk Programming"

The pdf is also available online, here.

ZAMO · 01-09-2009, 06:44 AM

Thank you colucix and jschiwal,

I am having this PDF for gawk for a very long time and used to go through it. It will be nice if I get a similar kind of one for "sed".

pixellany · 01-09-2009, 06:58 AM

The grymoire site linked earlier also has a good section on AWK.

Back to the questions:

Quote:

1.How to print a line ,say 28 only in a file using sed?
2.How to print from line 5-10 in a file ?

What you want is called "addressing". The general form is:

sed '<address1>,<address2> action'

either <address1> or <address2> can be a line number or a Regex. <address2> can also be a numerical increment or interval.

Examples:

Code:

sed -n '3p' filename     ##prints only line 3

sed -n '3,6p' filename    ##prints lines 3-6

sed -n '/the/p' filename    ##prints all lines containing "the"

sed -n '/the/,/end/p' filename    ##prints lines beginning with one containing "the" and ending with one containing "end"

finally, note that Gnu SED has many extensions that do not appear in the Unix tutorials. For this, look at "info sed" in a terminal, or Google for the official Gnu SED manual.