Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Replace first field of a line with previous filed of the line
Top Forums Shell Programming and Scripting Replace first field of a line with previous filed of the line Post 302840643 by usha rao on Tuesday 6th of August 2013 06:44:54 AM
Old 08-06-2013
Replace first field of a line with previous filed of the line
Hi Everyone,

I have a file as below:

Code:
IM2345638,sherfvf,usha,30
IM384940374,deiufbd,usha,30
IM323763822,cdejdkdnbds,theju,15
0,dhejdncbfd,us,20
IM398202038,dhekjdkdld,tj,30
0,foifsjd,u2,40

The output i need is as below


Code:
 
IM2345638,sherfvf,usha,30
IM384940374,deiufbd,usha,30
IM323763822,cdejdkdnbds,theju,15
IM323763822,dhejdncbfd,us,20
IM398202038,dhekjdkdld,tj,30
IM398202038,foifsjd,u2,40

Here I want to replace 0 with first field of previous line.

Not sure whether to use awk or sed

I tried this way but it didnt work as it is just printing first field.

Code:
for i in `cat test.txt | awk -F, '{print $1}'`; do if [ $i == 0 ]; then i=$var; fi; echo $i ; var=$i; done

Thanks in advance
Usha
Last edited by usha rao; 08-06-2013 at 07:46 AM.. Reason: code tags
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

replace [previous] line

Hi ,suppose I have a file title=dsafsadf ........ ....... year=1995 author=john smith ............ title=bbbbbb ........ ....... year=1988 author=alex I need to replace the title line with a expression that contains variables year and author. I want to use a python readline for loop.... (10 Replies)
Discussion started by: grossgermany
10 Replies

2. UNIX for Dummies Questions & Answers

Find and replace a field in the last line

I have a file 'test.out' with contents: 1|1|10|10|I|asdf| 2|1|10|10|I|sdfg| 4|1|10|10|I|hgfj| 34|0|10|10|I|sdg| I want to modify the fifth column with value 'I' to 'A' for only the last line. Below is what I expect to see: 1|1|10|10|I|asdf| 2|1|10|10|I|sdfg| ... (3 Replies)
Discussion started by: ChicagoBlues
3 Replies

3. UNIX for Dummies Questions & Answers

howto replace field in line

Hi all, I'm writing a script in bash where i'm reading line by line into variable, and the i want to replace the second filed in the line with another number, for example if the line looks like this: 10 20 30 40 50 it should look like this: 10 90 30 40 50 and put the new result inside... (1 Reply)
Discussion started by: morfix
1 Replies

4. Shell Programming and Scripting

Print a field from the previous line

plz help me!! I have this file , 3408 5600 3796 6035 4200 6285 4676 0 40 1554 200 1998 652 2451 864 2728 1200 0 I want it like if $2==0,replace it with field from the previous line+500 say here the o/p would be like 3408 5600 3796 6035 4200 6285... (16 Replies)
Discussion started by: Indra2011
16 Replies

5. Shell Programming and Scripting

Perl: Conditional replace based on previous and current value in a line

I need to read the contents of a file. Then I need to grep for a keyword and replace part of the grepped line based on the condition of previous and present line. Example input file: V { port1 = P; port2 = 0; shift_port = P0; /* if next shift_port is P0 I need... (9 Replies)
Discussion started by: naveen@
9 Replies

6. Shell Programming and Scripting

Compare Field in Current Line with Field in Previous

Hi Guys I have the following file Essentially, I am trying to find the right awk/sed syntax in order to produce the following 3 distinct files from the file above: Basically, I want to print the lines of the file as long as the second field of the current line is equal to the... (9 Replies)
Discussion started by: moutaye
9 Replies

7. Shell Programming and Scripting

sed to replace a field from a line with another field

i have something like this, cat filename.txt hui this si s"dfgdfg" omeone ipaddress="10.19.123.104" wel hope this works i want to replace only 10.19.123.104 with different ip say 10.19.123.103 i tried this sed -i "s/'ipaddress'/'ipaddress=10.19.123.103'/g" filename.txt ... (1 Reply)
Discussion started by: vivek d r
1 Replies

8. Shell Programming and Scripting

Search a string,get line and replace with second field

Hi, I need to search for source path in file2 , as per file1 and if found get the next line and take the field value and put it in URL value of file1. In file1, NF is not same for all the lines. file1: <type source="/home/USER/Desktop" Dest="/home/USER/DIR1/Desktop" URL="ssh/path"/> <type... (8 Replies)
Discussion started by: greet_sed
8 Replies

9. Shell Programming and Scripting

Replace a field with line number in file

I am working on a script to convert bank data to a csv file. I have the format done - columns etc. The final piece of the puzzle is to change the second field (after the R) of every line to reflect its' line number in the file. I am stumped. I can use awk on each line but need help looping through... (9 Replies)
Discussion started by: Melah Gindi
9 Replies

10. UNIX for Advanced & Expert Users

How to find a string in a line in UNIX file and delete that line and previous 3 lines ?

Hi , i have a file with data as below.This is same file. But actual file contains to many rows. i want to search for a string "Field 039 00" and delete that line and previous 3 lines in that file.. Can some body suggested me how can i do using either sed or awk command ? Field 004... (7 Replies)
Discussion started by: vadlamudy
7 Replies

LEARN ABOUT OSX

locale::codes::langvar

Locale::Codes::LangVar(3pm)				 Perl Programmers Reference Guide			       Locale::Codes::LangVar(3pm)

NAME

       Locale::Codes::LangVar - standard codes for language variation identification

SYNOPSIS

	  use Locale::Codes::LangVar;

	  $lvar = code2langvar('acm');		       # $lvar gets 'Mesopotamian Arabic'
	  $code = langvar2code('Mesopotamian Arabic'); # $code gets 'acm'

	  @codes   = all_langvar_codes();
	  @names   = all_langvar_names();

DESCRIPTION

       The "Locale::Codes::LangVar" module provides access to standard codes used for identifying language variations, such as those as defined in
       the IANA language registry.

       Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default IANA language
       registry codes will be used.

SUPPORTED CODE SETS

       There are several different code sets you can use for identifying language variations. A code set may be specified using either a name, or
       a constant that is automatically exported by this module.

       For example, the two are equivalent:

	  $lvar = code2langvar('en','alpha-2');
	  $lvar = code2langvar('en',LOCALE_CODE_ALPHA_2);

       The codesets currently supported are:

       alpha
	   This is the set of alphanumeric codes from the IANA language registry, such as 'arevela' for Eastern Armenian.

	   This code set is identified with the symbol "LOCALE_LANGVAR_ALPHA".

	   This is the default code set.

ROUTINES

       code2langvar ( CODE [,CODESET] )
       langvar2code ( NAME [,CODESET] )
       langvar_code2code ( CODE ,CODESET ,CODESET2 )
       all_langvar_codes ( [CODESET] )
       all_langvar_names ( [CODESET] )
       Locale::Codes::LangVar::rename_langvar  ( CODE ,NEW_NAME [,CODESET] )
       Locale::Codes::LangVar::add_langvar  ( CODE ,NAME [,CODESET] )
       Locale::Codes::LangVar::delete_langvar  ( CODE [,CODESET] )
       Locale::Codes::LangVar::add_langvar_alias  ( NAME ,NEW_NAME )
       Locale::Codes::LangVar::delete_langvar_alias  ( NAME )
       Locale::Codes::LangVar::rename_langvar_code  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::LangVar::add_langvar_code_alias  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::LangVar::delete_langvar_code_alias  ( CODE [,CODESET] )
	   These routines are all documented in the Locale::Codes::API man page.

SEE ALSO

       Locale::Codes
	   The Locale-Codes distribution.

       Locale::Codes::API
	   The list of functions supported by this module.

       http://www.iana.org/assignments/language-subtag-registry
	   The IANA language subtag registry.

AUTHOR

       See Locale::Codes for full author history.

       Currently maintained by Sullivan Beck (sbeck@cpan.org).

COPYRIGHT

	  Copyright (c) 2011-2012 Sullivan Beck

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.16.2							    2012-10-11					       Locale::Codes::LangVar(3pm)
All times are GMT -4. The time now is 05:03 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy