Sponsored Content
Full Discussion: SED Substitution
Top Forums Shell Programming and Scripting SED Substitution Post 302258194 by subhendu81 on Friday 14th of November 2008 02:36:03 AM
Old 11-14-2008
hi guys,

how can i convert multiple spaces to single space using sed in unix.

thanks in advance.

subhendu
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Substitution using sed

I know we can substitute a string using sed but how? For example: sed 's/(old variable)/(new variable)/ details.dat Am I suppose to put $old variable or whatever? Because I tried many times, it didnt work by putting $old variable. Am I suppose to enclose it with "" or ''? Please help (3 Replies)
Discussion started by: Ohji
3 Replies

2. UNIX for Dummies Questions & Answers

sed substitution

Hi, I have a set of files containing strings like I.TEST1_TEST2 or B.ESSA_ESSB for example. Does somebody know how to substitute these strings whith the same name and an extension "_V1" (ie. I.TEST1_TEST2_V1) using sed command or else ? (3 Replies)
Discussion started by: jo_aze
3 Replies

3. Shell Programming and Scripting

Substitution using SED

Hi , I am stuck up in the below scenario:- I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression. How can I use SED inside SHELL Scripting and command prompt as... (2 Replies)
Discussion started by: shubhranshu
2 Replies

4. Shell Programming and Scripting

SED Substitution

Hi , I am stuck up in the below scenario:- I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression. How can I use SED inside SHELL Scripting and command prompt as well to... (1 Reply)
Discussion started by: shubhranshu
1 Replies

5. Shell Programming and Scripting

sed substitution

Hi I am trying to do a text insertion in a text file at a particular line number in a shell script. However its not working. sed '122i\ > for j in \`echo $MyList\` ; do perl -pi -e\'s#01\/01\/2009#01\/01\/2011#\' $j ; done' $HOME/MyScript.ksh The Actual line to be inserted at line 122... (5 Replies)
Discussion started by: som.nitk
5 Replies

6. UNIX for Dummies Questions & Answers

Help with sed substitution

I'm a noob to unix, and I have a line of data like the following: title=Boston|tcolor=green|desc=Large city in New England|url=www.boston.com Is there a way to change a field value with sed substitution? (i.e. change tcolor=green to tcolor=blue) I figured out: sed... (19 Replies)
Discussion started by: stabby
19 Replies

7. Shell Programming and Scripting

Substitution with sed

I have a file with some numbers having single quotes around them which I want to remove. i.e. '923930' -> 23930 If it can be done without using sed thats fine. I have tried with sed but can't think how to replace this pattern on only the numbers (13 Replies)
Discussion started by: user_invalid
13 Replies

8. Shell Programming and Scripting

sed substitution

Hello, I have two files. File1 is normal txt file and File2 contains list of line numbers. e.g. File2: 3 6 9 ..... I need to replace a character in File1 in lines (taken from File2). For that I am using a "for" loop: for i in $(cat File2) do sed "$i s/Y/N/" File1 done but my... (3 Replies)
Discussion started by: shekhar2010us
3 Replies

9. UNIX for Dummies Questions & Answers

sed substitution

How can you use sed with a line of code that reads: 67899:Bill:Williams:Maple Dr.:45908600 Let us say we want to replace Maple Dr. with Oak St. (1 Reply)
Discussion started by: yonkers062986
1 Replies

10. Shell Programming and Scripting

sed substitution

Hi everyone, I need very simple sed command to change a parameter in a text file. I have a line in this text which is like set xx 0.5 A program reads this file and does some algebraic calculations. So to make a parameter scan I need to change the value of xx. I thought I can do... (7 Replies)
Discussion started by: hayreter
7 Replies
SED(1)							      General Commands Manual							    SED(1)

NAME
sed - stream editor SYNOPSIS
sed [ -n ] [ -g ] [ -e script ] [ -f sfile ] [ file ... ] DESCRIPTION
Sed copies the named files (standard input default) to the standard output, edited according to a script of commands. The -f option causes the script to be taken from file sfile; these options accumulate. If there is just one -e option and no -f's, the flag -e may be omitted. The -n option suppresses the default output; -g causes all substitutions to be global, as if suffixed g. A script consists of editing commands, one per line, of the following form: [address [, address] ] function [argument ...] In normal operation sed cyclically copies a line of input into a pattern space (unless there is something left after a command), applies in sequence all commands whose addresses select that pattern space, and at the end of the script copies the pattern space to the standard out- put (except under -n) and deletes the pattern space. An address is either a decimal number that counts input lines cumulatively across files, a that addresses the last line of input, or a con- text address, /regular-expression/, in the style of regexp(6), with the added convention that matches a newline embedded in the pattern space. A command line with no addresses selects every pattern space. A command line with one address selects each pattern space that matches the address. A command line with two addresses selects the inclusive range from the first pattern space that matches the first address through the next pattern space that matches the second. (If the second address is a number less than or equal to the line number first selected, only one line is selected.) Thereafter the process is repeated, looking again for the first address. Editing commands can be applied to non-selected pattern spaces by use of the negation function (below). An argument denoted text consists of one or more lines, all but the last of which end with to hide the newline. Backslashes in text are treated like backslashes in the replacement string of an command, and may be used to protect initial blanks and tabs against the stripping that is done on every script line. An argument denoted rfile or wfile must terminate the command line and must be preceded by exactly one blank. Each wfile is created before processing begins. There can be at most 120 distinct wfile arguments. a text Append. Place text on the output before reading the next input line. b label Branch to the : command bearing the label. If label is empty, branch to the end of the script. c text Change. Delete the pattern space. With 0 or 1 address or at the end of a 2-address range, place text on the output. Start the next cycle. d Delete the pattern space. Start the next cycle. D Delete the initial segment of the pattern space through the first newline. Start the next cycle. g Replace the contents of the pattern space by the contents of the hold space. G Append the contents of the hold space to the pattern space. h Replace the contents of the hold space by the contents of the pattern space. H Append the contents of the pattern space to the hold space. i text Insert. Place text on the standard output. n Copy the pattern space to the standard output. Replace the pattern space with the next line of input. N Append the next line of input to the pattern space with an embedded newline. (The current line number changes.) p Print. Copy the pattern space to the standard output. P Copy the initial segment of the pattern space through the first newline to the standard output. q Quit. Branch to the end of the script. Do not start a new cycle. r rfile Read the contents of rfile. Place them on the output before reading the next input line. s/regular-expression/replacement/flags Substitute the replacement string for instances of the regular-expression in the pattern space. Any character may be used instead of For a fuller description see regexp(6). Flags is zero or more of g Global. Substitute for all non-overlapping instances of the regular expression rather than just the first one. p Print the pattern space if a replacement was made. w wfile Write. Append the pattern space to wfile if a replacement was made. t label Test. Branch to the command bearing the label if any substitutions have been made since the most recent reading of an input line or execution of a If label is empty, branch to the end of the script. w wfile Write. Append the pattern space to wfile. x Exchange the contents of the pattern and hold spaces. y/string1/string2/ Transform. Replace all occurrences of characters in string1 with the corresponding character in string2. The lengths of string1 and string2 must be equal. !function Don't. Apply the function (or group, if function is only to lines not selected by the address(es). : label This command does nothing; it bears a label for b and t commands to branch to. = Place the current line number on the standard output as a line. { Execute the following commands through a matching only when the pattern space is selected. An empty command is ignored. EXAMPLES
sed 10q file Print the first 10 lines of the file. sed '/^$/d' Delete empty lines from standard input. sed 's/UNIX/& system/g' Replace every instance of by sed 's/ *$// drop trailing blanks /^$/d drop empty lines s/ */ replace blanks by newlines /g /^$/d' chapter* Print the files chapter1, chapter2, etc. one word to a line. nroff -ms manuscript | sed ' ${ /^$/p if last line of file is empty, print it } //N if current line is empty, append next line /^ $/D' if two lines are empty, delete the first Delete all but one of each group of empty lines from a formatted manuscript. SOURCE
/sys/src/cmd/sed.c SEE ALSO
ed(1), grep(1), awk(1), lex(1), sam(1), regexp(6) L. E. McMahon, `SED -- A Non-interactive Text Editor', Unix Research System Programmer's Manual, Volume 2. BUGS
If input is from a pipe, buffering may consume characters beyond a line on which a command is executed. SED(1)

Featured Tech Videos

All times are GMT -4. The time now is 11:06 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy