help with some commands


 
Thread Tools Search this Thread
# 1  
help with some commands

Hi!
i'd like from someone to explain me 'what is what' from these parts of code if it's possible.i'd like to understand them and their usage:
1)
Code:
sed '3d' filename

2)
Code:
sort –t: +0 -1 /etc/passwd

and also this:
Code:
tr ‘[0-9]’ ‘[+*10] ‘ < filename

thank you!

Last edited by strawhatluffy; 01-23-2012 at 03:27 PM.. Reason: Code tags!
# 2  
man pages

Have you looked at the man pages for each command?
For instance, type
Code:
man tr

will tell you about the tr command
# 3  
ok i got this about the tr command...
but what about the first command with sed and the second with sort?can you explain me these please?
# 4  
I think the sed expression there deletes the third line.

sed is a complicated language based on regular expressions and a complete explanation of its abilities would fill books. A small outline may be accessed with 'man sed'.
# 5  
maybe the command
Code:
sed '3d' filename

if i write it somewhere in my script replaces the sting '3d' withe the contents of the filename?
# 6  
no, it prints the contents of 'filename' to your terminal with the third line deleted, as described above.
# 7  
ok..i got it...'3d' in sed means delete the third line....and i thank you for this..
if i had sed in this form what this could mean:
Code:
sed '2s/home/george/' filename

whats the meaning of the '2s'??
 

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

9 More Discussions You Might Find Interesting

1. AIX

HACMP: difference between 'cl' commands and 'cli' commands

Hi all, I'm new in this forum. I'm looking for the difference between the HACMP commands with the prefix "cl" and "cli". The first type are under /usr/es/sbin/cluster/sbin directory and the second are under /usr/es/sbin/cluster/cspoc directory. I know that the first are called HACMP for AIX... (0 Replies)
Discussion started by: peppix
0 Replies

2. Shell Programming and Scripting

Can BASH execute commands on a remote server when the commands are embedded in shell

I want to log into a remote server transfer over a new config and then backup the existing config, replace with the new config. I am not sure if I can do this with BASH scripting. I have set up password less login by adding my public key to authorized_keys file, it works. I am a little... (1 Reply)
Discussion started by: bash_in_my_head
1 Replies

3. Shell Programming and Scripting

if, fi, then, and else commands

I am trying to create a script that will search for a file and if the file is there the script will end successfull, if the file is not found then the script will sleep for 60 then check for the file again. If the file is there the job will complete successfully, if it is still not there, the... (11 Replies)
Discussion started by: wereyou
11 Replies

4. Programming

code that reads commands from the standard i/p and executes the commands

Hello all, i've written a small piece of code that will read commands from standard input and executes the commands. Its working fine and is execting the commands well. Accepting arguments too. e.g #mkdir <name of the directory> The problem is that its not letting me change the directory i.e... (4 Replies)
Discussion started by: Phrozen Smoke
4 Replies

5. UNIX for Dummies Questions & Answers

vi commands

Hi, a. How can we replace one more spaces with a single space in vi? b. Replace one more spaces following a full stop or a comma with two spaces.? c. Delete all blank line? d. Insert > and a space at the start of every line in the file? e. Reverse the order of lines in a file? f. In a... (2 Replies)
Discussion started by: tictactoe
2 Replies

6. UNIX for Dummies Questions & Answers

need help with some commands please

In my unix machine I have the following setup. root 7 Dec 13 10:02 Beta10 -> current root 7 Dec 13 10:05 Beta11 -> current root 7 Dec 13 10:06 Beta12 -> current root 7 Dec 13 10:06 Beta13 -> current root 7 Dec 13 10:07 Beta14 -> current root 7 Dec 13 10:08 Beta15 -> current root 7... (2 Replies)
Discussion started by: mujtba
2 Replies

7. Shell Programming and Scripting

commands

anyone know the command to display the ten most common words, together with their number of occurences, in the manual entry for the ls command. It would be much useful (1 Reply)
Discussion started by: master_6ez
1 Replies

8. UNIX for Dummies Questions & Answers

some commands:

A junior member (F.O.G.) sent a question in about commands, and a member (jaru) responded with a list of commands. His list is great and helps me as well, thank you. However, where and how did raju get this list. As you can tell I am new this also. I used VMS years ago, and as I remember you... (4 Replies)
Discussion started by: jamin
4 Replies

9. UNIX for Dummies Questions & Answers

commands

hi, I'm completely new to FreeBds or unix in general, is there a really nice site to teach you the basic ommands to free BSD. I don't know what to do. =( (3 Replies)
Discussion started by: Special K
3 Replies

Featured Tech Videos