Sponsored Content
Top Forums UNIX for Dummies Questions & Answers Strange error: grep does not read from file Post 302557137 by FelipeAd on Tuesday 20th of September 2011 12:31:12 PM
Old 09-20-2011
Quote:
Originally Posted by Corona688
You can definitely read a line from a file in a while loop:
Code:
while read LINE
do
        echo -e "$LINE"
done < file1.txt

This will also prevent side-effects like variables being set inside the loop not being seen outside it.
It may sound silly but, since i want to use grep i actually want two input files, file1.txt and file2.txt

How do I do this? I mean in my case the command
Code:
cat file1.txt|while read line; do grep "$line" file2.txt;done

does not give me result. When i use the < though to set the input file it works.
So i wonder how can i do this with my two input files?
I hope i am not very confusing but i have no idea why WITH THE PARTICULAR FILES it does not work
 

10 More Discussions You Might Find Interesting

1. AIX

Strange error with file access permissions

All, I am trying to copy some data from /admin/reports/Sept/ccn/c_ivsstr01 to /home/users/myhomedir and I am getting an error I have never seen before: The file access permissions do not allow the specified action. The permissions on the file are -rw-r--r-- and I am the owner of the file... (3 Replies)
Discussion started by: kjbaumann
3 Replies

2. Shell Programming and Scripting

Read file then grep the line

Dear all, I am reading a file that has 1 column. While reading I must find the line references from the another file. The following shell doesn't works. Please help #!/bin/bash while read filename; do grep ${filename} fs_full.dat >> unprocfull.dat; done < unproc.dat But when... (2 Replies)
Discussion started by: mr_bold
2 Replies

3. UNIX for Advanced & Expert Users

Strange read "error"

Good day. I really hope U can help me with this as I'm stumped! In the command line eg: read X; echo $x . Works perfectly fine. Then running the same thing in my script it sometimes exiqute immediatly after pressing enter and continuiing. Not exiting the script I re-run the "read" section.... (1 Reply)
Discussion started by: Blooper1980
1 Replies

4. Shell Programming and Scripting

read in variable data from another file - grep

Hello! I think this should be an easy solution. I have a large file with many fields of data. The first field has a unique identifier (a subject number) for every record for a chunk of data. Something like this: There were ten experimental conditions (ec), but the ec is identified by only... (11 Replies)
Discussion started by: ccox85
11 Replies

5. Shell Programming and Scripting

Strange error while splitting a file

Hi folks I am facing a strange error while splitting a '|' delimited file 'file1' based on column '3'. (File is 40 columns wide). I wish to create as many files 'file_n' from the file 'file1' as distinct values of the column '3'; in 'file1' eg: file1: qwe|qweqw|123|fg... (3 Replies)
Discussion started by: powerslave
3 Replies

6. Shell Programming and Scripting

Grep a file that may contain strange characters

Hello unix users :) I am trying to grep a string from a file that both the file and the string may have characters in them that are quite... strange, like würzburger. Well, bash reads this as W%C3%BCrzburger For example, if i do wget W%C3%BCrzburger the output is: --2012-01-08... (2 Replies)
Discussion started by: hakermania
2 Replies

7. Shell Programming and Scripting

read from file and grep using shell

Hi Guys, I have a small script which greps for the username reading from stdinput. ./file.sh pattern pattern=$1 grep "blah blah.*$pattern" /home/user/log.txt Instead of typing the pattern everytime i want to read the pattern from a file inside the shell script and execute the... (5 Replies)
Discussion started by: Irishboy24
5 Replies

8. UNIX for Beginners Questions & Answers

Read a file and send mail based on grep

Hi All, I am having a job and I need to send email when the job is running. On any other case (success,fail) I don't needed to send email. I check with BMC they told they dont have that in the version I am using. So I created a dependent job and grepped for the status and sent email. My... (1 Reply)
Discussion started by: arunkumar_mca
1 Replies

9. Shell Programming and Scripting

How to read each file grep a value from that?

Hi Team, in /tmp folder i have thousands of log files i want to read each file and grep a value called "Calling This". Each logfile name is different but it ends with .log. How can i achieve this? Please excuse if i did any mistake by not following forum standards. I will surely follow... (10 Replies)
Discussion started by: darling
10 Replies

10. UNIX for Advanced & Expert Users

Need help for faster file read and grep in big files

I have a very big input file <inputFile1.txt> which has list of mobile no inputFile1.txt 3434343 3434323 0970978 85233 ... around 1 million records i have another file as inputFile2.txt which has some log detail big file inputFile2.txt afjhjdhfkjdhfkd df h8983 3434343 | 3483 | myout1 |... (3 Replies)
Discussion started by: reldb
3 Replies
diff3(1)						      General Commands Manual							  diff3(1)

Name
       diff3 - 3-way differential file comparison

Syntax
       diff3 [-ex3] file1 file2 file3

Description
       The command compares three versions of a file, and publishes the ranges of text that disagree, flagged with the following codes:

	  ====	      all three files differ

	  ====1       file1 is different

	  ====2       file2 is different

	  ====3       file3 is different

       The type of change needed to convert a given range of a given file to some other is indicated in one of these ways:

	  f : n1 a    Text is to be appended after line number n1 in file f, where f = 1, 2, or 3.

	  f : n1 , n2 c
		      Text is to be changed in the range line n1 to line n2.  If n1 = n2, the range may be abbreviated to n1.

       The original contents of the range follows immediately after a c indication.  When the contents of two files are identical, the contents of
       the lower-numbered file is suppressed.

Options
       -3   Produces an editor script containing the changes between file1 and file2 that are to be incorporated into file3.

       -e	   Produces an editor script containing the changes between file2 and file3 that are to be incorporated into file1.

       -x	   Produces an editor script containing the changes among all three files.

Examples
       Under the -e option, publishes a script for the editor that incorporates into file1 all changes between file2 and  file3  -  that  is,  the
       changes	that would normally be flagged ==== and ====3.	Option -x (-3) produces a script to incorporate only changes flagged ==== (====3).
       The following command applies the resulting script to `file1':
       (cat script; echo '1,$p') | ed - file1

Restrictions
       Text lines that consist of a single `.'	defeat -e.

Files
       /tmp/d3?????
       /usr/lib/diff3

See Also
       cmp(1), comm(1), diff(1), dffmk(1), join(1), sccsdiff(1), uniq(1)

																	  diff3(1)
All times are GMT -4. The time now is 04:37 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy