Sponsored Content
Top Forums UNIX for Beginners Questions & Answers How to read file line by line in shell script? Post 303044685 by jgt on Sunday 1st of March 2020 08:49:24 PM
Old 03-01-2020
Instead of reading the input a line at a time:
Code:
read a
while read a b c d e f
do
    echo USER= $a CPU= $c
done

run as

Code:
ps aux |script_above



You end up only reading the output of ps once instead of multiple times.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

shell script to read a line in gps receiver log file and append that line to new file

Hi, I have gps receiver log..its giving readings .like below Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. GPSD,R=1 $GPGSV,3,1,11,08,16,328,40,11,36,127,00,28,33,283,39,20,11,165,00*71... (3 Replies)
Discussion started by: gudivada213
3 Replies

2. UNIX for Dummies Questions & Answers

shell script to read file line by line

Hi, I need to read a text file from shell script line by line and copy the feilds of each line. Below is the complete requirement. I've text file which contains ... pgm1 file11 file12 file13 pgm2 file21 file22 pgm3 file31 file32 file33 I'll give input as... (4 Replies)
Discussion started by: ani12345
4 Replies

3. Shell Programming and Scripting

how can u read a file line by line in shell script ?

hello , plz help for below script req:- how can we read a file line by line in shell script ? (4 Replies)
Discussion started by: abhigrkist
4 Replies

4. Shell Programming and Scripting

Shell script to read a text file line by line & process it...

Hi , I am trying to write an shell, which reads a text file (from a location) having a list of numbers of strictly 5 digits only ex: 33144 Now my script will check : 1) that each entry is only 5 digits & numeric only, no alphabets, & its not empty. 2)then it executes a shell script called... (8 Replies)
Discussion started by: new_to_shell
8 Replies

5. Shell Programming and Scripting

Shell script to read multiple options from file, line by line

Hi all I have spent half a day trying to create a shell script which reads a configuration file on a line by line basis. The idea of the file is that each will contain server information, such as IP address and various port numbers. The line could also be blank (The file is user created). Here... (1 Reply)
Discussion started by: haggismn
1 Replies

6. Shell Programming and Scripting

HELP: Shell Script to read a Log file line by line and extract Info based on KEYWORDS matching

I have a LOG file which looks like this Import started at: Mon Jul 23 02:13:01 EDT 2012 Initialization completed in 2.146 seconds. -------------------------------------------------------------------------------- -- Import summary for Import item: PolicyInformation... (8 Replies)
Discussion started by: biztank
8 Replies

7. Shell Programming and Scripting

How to read a two files, line by line in UNIX script and how to assign shell variable to awk ..?

Input are file and file1 file contains store.bal product.bal category.bal admin.bal file1 contains flip.store.bal ::FFFF:BADC:CD28,::FFFF:558E:11C5,6,8,2,1,::FFFF:81C8:CA8B,::FFFF:BADC:CD28,1,0,0,0,::FFFF:81C8:11C5,2,1,0,0,::FFFF:81DC:3111,1,0,1,0 store.bal.... (2 Replies)
Discussion started by: veeruasu
2 Replies

8. Shell Programming and Scripting

Bash script to read a file from particular line till required line and process

Hi All, Am trying to write wrapper shell/bash script on a utility tool for which i need to pass 2 files as arugment to execute utility tool. Wraper script am trying is to do with above metion 2 files. utility tool accepts : a. userinfo file : which contains username b. item file : which... (2 Replies)
Discussion started by: Optimus81
2 Replies

9. Shell Programming and Scripting

With script bash, read file line per line starting at the end

Hello, I'm works on Ubuntu server My goal : I would like to read file line per line, but i want to started at the end of file. Currently, I use instructions : while read line; do COMMAND done < /var/log/apache2/access.log But, the first line, i don't want this. The file is long... (5 Replies)
Discussion started by: Fuziion
5 Replies

10. Shell Programming and Scripting

Shell script UNIX to read text file line by line

i have a text file as belows, it includes 2 columns, 1st is the column name, 2nd is the file_name data_file.txt column_name file_name col1 file1 col2 file2 col3 file1 col4 file1 col5 file2 now, i would like to... (4 Replies)
Discussion started by: tester111
4 Replies
val(1)							      General Commands Manual							    val(1)

Name
       val - validate SCCS file

Syntax
       val -
       val [-s] [-rSID] [-mname] [-ytype] files

Description
       The  command  determines  if the specified file is an SCCS file meeting the characteristics specified by the optional argument list.  Argu-
       ments to may appear in any order.  The arguments consist of keyletter arguments that begin with a ``-'' and named files.

       The command has a special argument, ``-,'' which causes reading of the standard input until an end-of-file  condition  is  detected.   Each
       line read is independently processed, as if it were a command line argument list.

       The  command  generates diagnostic messages on the standard output for each command line and file processed and also returns a single 8-bit
       code upon exit as described below.

Options
       The effects of any keyletter argument apply independently to each named file on the command line.  The keyletter arguments are  defined	as
       follows:

	      -  Causes stdin to be read until end of file.

	      -s Suppresses all error messages.

	      -rSID
		 Indicates  specified  delta  version  number.	A check is made to determine if the SID is ambiguous, for example, r1 is ambiguous
		 because it physically does not exist but implies 1.1, 1.2, and so forth, which may exist) or invalid, for example, r1.0 or r1.1.0
		 are  invalid  because neither case can exist as a valid delta number).  If the SID is valid and not ambiguous, a check is made to
		 determine if it actually exists.

	      -mname
		 Compares specified value with the SCCS val.1 keyword.

	      -ytype
		 Compares specified type with SCCS  keyword.

       The 8-bit code returned by is a disjunction of the possible errors.  It can be interpreted as a bit string where set bits  are  interpreted
       (from left to right) as:

	      bit 0 = missing file argument
	      bit 1 = unknown or duplicate keyletter argument
	      bit 2 = corrupted SCCS file
	      bit 3 = can't open file or file not SCCS
	      bit 4 = SID is invalid or ambiguous
	      bit 5 = SID does not exist
	      bit 6 = %Y%, -y mismatch
	      bit 7 = %M%, -m mismatch

       Note that can process two or more files on a given command line and can process multiple command lines when reading the standard input.	In
       these cases, an aggregate code is returned - a logical OR of the codes generated for each command line and file processed.

Restrictions
       The command can process up to 50 files on a single command line.  Any number above 50 produces a core dump.

Diagnostics
       Use for explanations.

See Also
       admin(1), delta(1), get(1), prs(1), sccs(1)
       Guide to the Source Code Control System

																	    val(1)
All times are GMT -4. The time now is 09:57 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy