Sponsored Content
Full Discussion: understanding sed command
Top Forums UNIX for Dummies Questions & Answers understanding sed command Post 302572799 by Klashxx on Friday 11th of November 2011 06:21:52 AM
Old 11-11-2011
You're telling sed ( with the first s ) to substitute all strings that matches the first pattern (things at left of the second slash) whith nothing (right of the second slash).

So if you want to delete all the strings at the right of the % , you can use this :

Code:
sed  's/[^%]*$//' txt

This User Gave Thanks to Klashxx For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

understanding the sed command

Guys, I am trying to understand the sed command here. adx001 $ a=/clocal/dctrdata/user/dctrdat1/trdroot/recouncil adx001 $ b=`echo $a | sed 's/\//\\\\\//g'` adx001 $ echo $b \/clocal\/dctrdata\/user\/dctrdat1\/trdroot\/recouncil The sed command i took it from the script. Please... (3 Replies)
Discussion started by: mac4rfree
3 Replies

2. Shell Programming and Scripting

Help Needed in understanding this command

Hi All, I search the forum for my query, Glad that got solution to it. But i really want to understand how does this command work. sed -e ':a' -e 's/\("*\),\(*"\)/\1~\2/;ta' Basically it is replacing all the comma(,) characters in between quotes with a tilde. Specially what does ':a' ,... (2 Replies)
Discussion started by: DSDexter
2 Replies

3. Shell Programming and Scripting

understanding the kill command

Hi Guys, I like to know if i have a process which triggers 10 different child processes. How to identify out of the 11 processes running which is the parent process and what are the child process? And if i kill the parent process will the child process be killed.. if not is there a way to... (2 Replies)
Discussion started by: mac4rfree
2 Replies

4. UNIX for Dummies Questions & Answers

Help understanding sed

I am trying to create a basic script that converts an Oracle script into a Sybase script. The only things im changing are Datatypes and the to_char and to_date functions. I am not really 100% sure of the way it works. I have tried running the functions through a loop to replace each word line... (6 Replies)
Discussion started by: Makaer
6 Replies

5. Shell Programming and Scripting

understanding mv command

hi i was moving a file from one directory to another with the following cmmand mv /home/hsghh/dfd/parent/file.txt . while doing so i i accidently mv /home/hsghh/dfd/dfd . although i gave ctrl c and terminate the move command some of the file are missing in the parent directory and... (1 Reply)
Discussion started by: saravanan71184
1 Replies

6. Solaris

Understanding 'du' command

Hi I have a questions related 2 commands : 'du' and 'ls'. Why is the difference between output of 'du' and 'ls' cmd's ? Command 'du' : ------------------ jakubn@server1 /home/jakubn $ du -s * 4 engine.ksh 1331 scripts 'du -s *' ---> shows block count size on disk (512 Bytes... (5 Replies)
Discussion started by: presul
5 Replies

7. UNIX for Dummies Questions & Answers

Understanding nm command output

After running nm command on any object file from out put can we get to know that wheather a symbol is a call to a function or definition of function ? I am searching a class and function definitions inside many .so files. I have 3 files which contain the symbol but I don't know wheather they... (2 Replies)
Discussion started by: yatrik007
2 Replies

8. Shell Programming and Scripting

help understanding regex with grep & sed

I have the following line of code that works wonders. I just don't completely understand it as I am just starting to learn regex. Can you help me understand exactly what is happening here? find . -type f | grep -v '^\.$' | sed 's!\.\/!!' (4 Replies)
Discussion started by: trogdortheburni
4 Replies

9. Shell Programming and Scripting

Understanding sed

Hi, can some one suggest me,how "sed" is managed to delete the second field here. Any explanation on , how the below code is working would be appreciated. sed 's/^\(*\)::/\1::/' /etc/passwd sed 's/*:/:/2' /etc/passwd (14 Replies)
Discussion started by: panyam
14 Replies

10. Shell Programming and Scripting

Need Quick help on Understanding sed Regex

Hi Guys, Could you please kindly explain what exactly the below SED command will do ? I am quite confused and i assumed that, sed 's/*$/ /' 1. It will remove tab and extra spaces .. with single space. The issue is if it is removing tab then it should be Î right .. please assist.... (3 Replies)
Discussion started by: Nandy
3 Replies
SHELLEXP(3)						     Library Functions Manual						       SHELLEXP(3)

NAME
shellexp - match string against a cruft filter pattern SYNOPSIS
extern int shellexp(const char *string, const char *pattern); DESCRIPTION
The shellexp() function is similar to fnmatch(3), but works with cruft patterns instead of standard glob(7) patterns. The function returns a true value if string matches the cruft pattern pattern, and a false value (0) otherwise. Returns -1 in case of pattern syntax error. Cruft patterns are similar to glob(7) patterns, but are not fully compatible. The following special characters are supported: ? (a question mark) matches exacly one character of string other than a slash. * matches zero or more characters of string other than a slash. /** or /**/ matches zero or more path components in string. Please note that you can only use ** when directly following a slash, and further- more, only when either directly preceding a slash or at the very end of pattern. A ** followed by anything other than a slash makes pattern invalid. A ** following anything else than a slash reduces it to having the same effect as *. [character-class] Matches any character between the brackets exactly once. Named character classes are NOT supported. If the first character of the class is ! or ^, then the meaning is inverted (matches any character NOT listed between the brackets). If you want to specify a literal closing bracket in the class, then specify it as the first (or second, if you want to negate) character after the opening bracket. Also, simple ASCII-order ranges are supported using a dash character (see examples section). Any other character matches itself. EXAMPLES
/a/b*/*c matches /a/b/xyz.c, as well as /a/bcd/.c, but not /a/b/c/d.c. /a/**/*.c matches all of the following: /a/a.c, /a/b/a.c, /a/b/c/a.c and /a/b/c/d/a.c. /a/[0-9][^0-9]* matches /a/1abc, but not /a/12bc. BUGS
Uses constant-length 1000 byte buffers to hold filenames. Also uses recursive function calls, which are not very efficient. Does not vali- date the pattern before matching, so any pattern errors (unbalanced brackets or misplaced **) are only reported when and if the matching algorithm reaches them. SEE ALSO
fnmatch(3), glob(3), cruft(8) and dash-search(1). AUTHOR
This manual page was written by Marcin Owsiany <porridge@debian.org>, for the Debian GNU/Linux system (but may be used by others). October 17, 2007 SHELLEXP(3)
All times are GMT -4. The time now is 08:07 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy