If all of the files are in a single directory (not spread out among subdirectories), you could try the following first:
or, if you just want the names of files containing that string (with a case insensitive match):
These might file with "argument list too long" errors depending on how many thousands of files you have, but it is easy to try it. And, if it works, it will hundreds or thousands of times faster that performing a grep on each file individually. If they won't work, you'll know quickly.
Note that I added a -F option to grep. Searching for fixed strings (even if you're doing a case-insensitive match), is faster than going through the extra complexity of matching regular expressions.
If all of the log entries use the same case, dropping the -i option will also make it run faster.
This User Gave Thanks to Don Cragun For This Post:
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)
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)
I have inherited the UNIX scripting duties for our team and have only been at this for a few months so I apologize for what may be a simple question.
We have a script we are reworking. Part of this script takes a parameter and reads a csv file. When it finds a matching line, the cut command is... (4 Replies)
Hi all,
I would like to ask whether in Unix shell/perl have any functions or command to allow grep/cat/read a file inside compressed .tgz without extract it?
I know we can tar tvf a compressed tgz but this only allow we read the path/filename contained inside the tarball. If we want to read... (3 Replies)
I have two files
file1.txt
angie
mary
susan
file2.txt
angie blond
mary brunnet
susan red
christine blackI want to get this output
angie blond
mary brunnet
susan redI write
grep --file=file1.txt file2.txtand i get no results
i also wrote
cat file1.txt|while read line... (19 Replies)
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)
Hi,
I'm trying to read a fille into a loop and grep for a string and print the last field of the string in the second file. Then redirect the output to another file but keeping the output in the same order as the original file.
I've tried using the following but the ouput from this does not... (3 Replies)
Hi,
I have a number of files containing the information below.
"""""
Fundallinfo
6.3950 14.9715 14.0482
"""""
I would like to grep for Fundallinfo and use it to read the next line? I ideally would like to read the three numbers that follow in the next line and... (2 Replies)
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)
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
LEARN ABOUT V7
grep
GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file.
Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full
regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it
is fast and compact.
The following options are recognized.
-v All lines but those matching are printed.
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-s No output is produced, only status.
-h Do not print filename headers with output lines.
-y Lower case letters in the pattern will also match upper case letters in the input (grep only).
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is
safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character matches that character.
The character ^ ($) matches the beginning (end) of a line.
A . matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
SEE ALSO ed(1), sed(1), sh(1)DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited to 256 characters; longer lines are truncated.
GREP(1)