grep should perform way better than awk in pattern matching.
You must be using a very good grep and a very bad awk if you see a significant difference in simply printing matching lines.
Not only do I not see a big difference, but awk wins one of the tests.
Using a pair of GNU implementations (neither of which is renowned for speed):
Code:
$ awk --version | head -n1
GNU Awk 4.1.0, API: 1.0 (GNU MPFR 3.1.2, GNU MP 4.3.2)
$ grep --version | head -n1
GNU grep 2.6.3
Fixed string:
Code:
$ time seq 500000 | grep -c 434
2484
real 0m15.266s
user 0m14.685s
sys 0m0.061s
$ time seq 500000 | grep -Fc 434
2484
real 0m15.266s
user 0m14.919s
sys 0m0.015s
$ time seq 500000 | awk '/434/ {++i} END {print i}'
2484
real 0m14.813s
user 0m14.888s
sys 0m0.030s
Regular expression with wildcard:
Code:
$ time seq 500000 | grep -c '4.*4'
73535
real 0m14.844s
user 0m15.968s
sys 0m0.015s
$ time seq 500000 | awk '/4.*4/ {++i} END {print i}'
73535
real 0m15.047s
user 0m14.998s
sys 0m0.076s
Hi there Gurus,
I have the following ftp script:
$ more ftp_dump_arch4.sh
#! /usr/bin/ksh
# Constant variables
HOST='xx.xx.xx.xx'
USER='user'
PASSWD='password'
dir='/export/file'
ftp_log='/tmp'
ftp -n $HOST > $ftp_log/ftp.log << END
user $USER $PASSWD
verbose
lcd $dir
bin (3 Replies)
Hi,
filenames:
contains name of list of files to search in.
placelist
contains the names of places to be searched in all files in "filenames"
for i in $(<filenames)
do
egrep -f placelist $i
if ]
then
echo $i
fi
done >> outputfile
Output i am getting: (0 Replies)
Hello,
I am trying to write a bash shell script that does the following:
1.Finds all *.txt files within my directory of interest
2. reads each of the files (25 files) one by one (tab-delimited format and have the same data format)
3. skips the first 10 rows of the file
4. extracts and... (4 Replies)
Hi everyone!!
I have a database table, which has file_name as one of its fields.
Example:
File_ID File_Name Directory Size
0001 UNO_1232 /apps/opt 234
0002 UNO_1234 /apps/opt 788
0003 UNO_1235 /apps/opt 897
0004 UNO_1236 /apps/opt 568
I have to... (3 Replies)
Hi guys,
say I have a few files in a directory (58 text files or somthing)
each one contains mulitple strings that I wish to replace with other strings
so in these 58 files I'm looking for say the following strings:
JAM (replace with BUTTER)
BREAD (replace with CRACKER)
SCOOP (replace... (19 Replies)
Hi,
I'd like to process multiple files. For example:
file1.txt
file2.txt
file3.txt
Each file contains several lines of data. I want to extract a piece of data and output it to a new file.
file1.txt ----> newfile1.txt
file2.txt ----> newfile2.txt
file3.txt ----> newfile3.txt
Here is... (3 Replies)
Hi,
I have a bunch of records within a directory where each one has this form:
(example file1)
1 2 50 90 80 90 43512 98 0909 79869 -9 7878 33222 8787 9090 89898 7878 8989 7878 6767 89 89 78676 9898 000 7878 5656 5454 5454
and i want for all of these files to be... (3 Replies)
Hi,
I have a directory /home/datasets/ which contains a bunch (720) of subdirectories called hour_1/ hour_2/ etc..etc.. in each of these there is a single text file called (hour_1.txt in hour_1/ , hour_2.txt for hour_2/ etc..etc..) and i would like to do some text processing in them.
Each of... (20 Replies)
Hi,
Is it possible to have multiple files with the same name in a same unix directory?
Eg., in the path \tmp, can we have 2 files with the same name as SALES_data_20120124.TXT?
I heard it is possible if the user id that is created the files are different and with some ids, a new gets... (1 Reply)
Hi!
I'm new in awk and I need some help.
I have a folder with a lot of files and I need that awk do something in each file and print a new file with the output. The input file name should be modified when I print the outpu files.
Thanks in advance for help!
:-)
ciao (5 Replies)
Discussion started by: gabrysfe
5 Replies
LEARN ABOUT X11R4
zgrep
ZGREP(1) General Commands Manual ZGREP(1)NAME
zgrep - search possibly compressed files for a regular expression
SYNOPSIS
zgrep [ grep_options ] [ -e ] pattern filename...
DESCRIPTION
Zgrep invokes grep on compressed or gzipped files. These grep options will cause zgrep to terminate with an error code:
(-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*). All other options specified are passed directly to grep. If no file is specified, then the
standard input is decompressed if necessary and fed to grep. Otherwise the given files are uncompressed if necessary and fed to grep.
If the GREP environment variable is set, zgrep uses it as the grep program to be invoked.
EXIT CODE
2 - An option that is not supported was specified.
AUTHOR
Charles Levert (charles@comm.polymtl.ca)
SEE ALSO grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1)ZGREP(1)