Q. How do I number each line of a text file? How do I write a shell script to display text file with line numbers added?
A. You don't have to write a shell script to add numbers to text file or code sample. You can use nl command which write each FILE to screen with line numbers added.
nl command example
Type the command as follows:
$ nl /etc/passwd
Sample output:
1 root:x:0:0:root:/root:/bin/bash
2 daemon:x:1:1:daemon:/usr/sbin:/bin/sh
3 bin:x:2:2:bin:/bin:/bin/sh
4 sys:x:3:3:sys:/dev:/bin/sh
5 sync:x:4:65534:sync:/bin:/bin/sync
6 games:x:5:60:games:/usr/games:/bin/sh
7 man:x:6:12:man:/var/cache/man:/bin/sh
8 lp:x:7:7:lp:/var/spool/lpd:/bin/sh
9 mail:x:8:8:mail:/var/mail:/bin/sh
10 news:x:9:9:news:/var/spool/news:/bin/sh
......
...
40 quagga:x:119:126:Quagga routing suite,,,:/var/run/quagga/:/bin/false
41 oracle:x:1004:1004::/usr/lib/oracle/xe:/bin/bash
42 telnetd:x:112:120::/nonexistent:/bin/false
nl command has few more options:
$ nl --help
Output:
Usage: nl [OPTION]... [FILE]...
Write each FILE to standard output, with line numbers added.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too.
-b, --body-numbering=STYLE use STYLE for numbering body lines
-d, --section-delimiter=CC use CC for separating logical pages
-f, --footer-numbering=STYLE use STYLE for numbering footer lines
-h, --header-numbering=STYLE use STYLE for numbering header lines
-i, --page-increment=NUMBER line number increment at each line
-l, --join-blank-lines=NUMBER group of NUMBER empty lines counted as one
-n, --number-format=FORMAT insert line numbers according to FORMAT
-p, --no-renumber do not reset line numbers at logical pages
-s, --number-separator=STRING add STRING after (possible) line number
-v, --first-page=NUMBER first line number on each logical page
-w, --number-width=NUMBER use NUMBER columns for line numbers
--help display this help and exit
--version output version information and exit
By default, selects -v1 -i1 -l1 -sTAB -w6 -nrn -hn -bt -fn. CC are
two delimiter characters for separating logical pages, a missing
second character implies :. Type \\ for \. STYLE is one of:
a number all lines
t number only nonempty lines
n number no lines
pBRE number only lines that contain a match for the basic regular
expression, BRE
FORMAT is one of:
ln left justified, no leading zeros
rn right justified, no leading zeros
rz right justified, leading zerosFeatured Articles:
- 20 Linux System Monitoring Tools Every SysAdmin Should Know
- 20 Linux Server Hardening Security Tips
- My 10 UNIX Command Line Mistakes
- Linux: 20 Iptables Examples For New SysAdmins
- 25 PHP Security Best Practices For Sys Admins
- The Novice Guide To Buying A Linux Laptop
- 10 Greatest Open Source Software Of 2009
- Top 5 Email Client For Linux, Mac OS X, and Windows Users
- Top 20 OpenSSH Server Best Security Practices
- Top 10 Open Source Web-Based Project Management Software
- Top 5 Linux Video Editor Software
Facebook it - Tweet it - Print it -
{ 10 comments… read them below or add one }
You can do that with cat also.
cat -n
I used cat -n till now. Not so much features but enough for using it in some scripts.
Tobi / Halttula: thanks for pointing out cat -n switch.
“pr” can do it too
grep -n
but this not so good
Hello, I’m new in linux, please help me to write this shell script and explain them
1- Write a shell script (trans.sh) that :
- Take as command-line options any number of text files
-Read in each of these files, converts all the letters to uppercase, and then stores the results in a file of the same name but with a .caps extension
2- Write a script (execadd.sh) that will take a single filename as an argument and adds execute permission to the file for the user, but only if the file is a regular file.
Your script must check to see that there is exactly one argument. If there are no arguments or more than one arguments, your script must produce a “usage” message that tells how to use the script.
How would you connect from one UNIX terminal to another using SSH can any one explain with example.
use ssh:
How would you make your umask setting permanent?
how to remove number each line of a text file?