Sponsored Content
Top Forums Shell Programming and Scripting perl - how do i find out if a file doesn't contain a pattern? Post 302136498 by mjays on Tuesday 18th of September 2007 05:32:21 AM
Old 09-18-2007
perl - how do i find out if a file doesn't contain a pattern?

how do i check a file for a pattern and perform an action if it doesn't exist?

i know how to search a file for a pattern. you just place it in an array like so.
Code:
#!/usr/bin/perl
my $data_file = "file.txt";
open DATA, "$data_file";
my @array_of_data = <DATA>;
        if ($_ =~ m/pattern/i) {
        print "\nfile contains pattern";
        }
close DATA

however, if you want to find out if a pattern doesn't exist, the search will always be true because each line is read separately and not all lines in the file contain the pattern.

how do search the whole file for the non-existence of the pattern?

hope i've made sense?
 

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

HELP! PERL script to find matched pattern

Hi all, I just learnt Perl and I encountered a problem in my current project. For a verilog file, i am required to write a PERL script that could match pattern to output nitrolink and nitropack. I wont know what name to grep except the pattern below. the verilog file: nitrolink nitrolink... (1 Reply)
Discussion started by: kimhuat
1 Replies

2. Shell Programming and Scripting

How to find this pattern in a file

hi all i have a file in my box, which is so huge and full file is in a single line. In this file i have to look for a pattern "ABC01234567" In this above mentioned pattern ABC is fixed and number might change . it will a eight digit random number Thanks so much for all you help ... (1 Reply)
Discussion started by: Prateek007
1 Replies

3. Shell Programming and Scripting

To find a pattern in file

Hi, I would like to find a pattern in a file as follows: I would like to find "or" "OR" "and" "AND" between two numeric values. I have tried this: grep '**or*' But does not work. Appreciate help on this. (4 Replies)
Discussion started by: pinnacle
4 Replies

4. UNIX for Dummies Questions & Answers

PERL pattern matching in a file

Hi Gurus, I have a file like below.. I have to match each with predefined pattern. If matches then have to write the entire record to a separate file. If not make the value as NULL and write the entire record into another file. | is the delimiter ravi123|2344|M R123Vi|2345|F... (8 Replies)
Discussion started by: pvksandeep
8 Replies

5. Shell Programming and Scripting

how to find a pattern from an external file in a directory containing multiple file recursively

Hi, Need your help in this. I have an input file that has multiple enrollment_number, somewhat like 1234567 8901234 9856321 6732187 7623465 Now i have to search and delete these enrollment_number recursively from all the files that are within multiple sub-directories of a... (10 Replies)
Discussion started by: mukulverma2408
10 Replies

6. Shell Programming and Scripting

Why regex pattern doesn't work in find?

$ find /opt/data_* -maxdepth 3 -type d -name "main*" 2> /dev/null /opt/data_025/maindblogs /opt/data_026/maindblogs /opt/data_027/maindblogs /opt/data_028/maindblogs $ find /opt/data_* -maxdepth 3 -type d -name "rvlogs*" 2> /dev/null /opt/data_002/prod/rvlogs2_archive... (4 Replies)
Discussion started by: urello
4 Replies

7. Shell Programming and Scripting

Find file of particular pattern

Hi All, I have a file PSU_ 20130805_201308041234522 i want to search this file where variable day=20130805 and curday=20130804 after currday date some numbers will be added.how to search this file by using day and curday. Thanks in advance. (3 Replies)
Discussion started by: pracheth
3 Replies

8. Shell Programming and Scripting

How to find a file with a specific pattern for current sysdate & upon find email the details?

I need assistance with following requirement, I am new to Unix. I want to do the following task but stuck with file creation date(sysdate) Following is the requirement I need to create a script that will read the abc/xyz/klm folder and look for *.err files for that day’s date and then send an... (4 Replies)
Discussion started by: PreetArul
4 Replies

9. Shell Programming and Scripting

sed -- Find pattern -- print remainder -- plus lines up to pattern -- Minus pattern

The intended result should be : PDF converters 'empty line' gpdftext and pdftotext?xml version="1.0"?> xml:space="preserve"><note-content version="0.1" xmlns:/tomboy/link" xmlns:size="http://beatniksoftware.com/tomboy/size">PDF converters gpdftext and pdftotext</note-content>... (9 Replies)
Discussion started by: Klasform
9 Replies
FC-PATTERN(1)															     FC-PATTERN(1)

NAME
fc-pattern - parse and show pattern SYNOPSIS
fc-pattern [ -cdVh ] [ --config ] [ --default ] [ [ -f format ] [ --format format ] ] [ --version ] [ --help ] [ pattern [ element... ] ] DESCRIPTION
fc-pattern parses pattern (empty pattern by default) and shows the parsed result. If --config is given, config substitution is performed on the pattern before being displayed. If --default is given, default substitution is performed on the pattern before being displayed. If any elements are specified, only those are printed. OPTIONS
This program follows the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of options is included below. -c Perform config substitution on pattern. -d Perform default substitution on pattern. -f Format output according to the format specifier format. -V Show version of the program and exit. -h Show summary of options. pattern Parses and displays pattern (uses empty pattern by default). element If set, the element property is displayed for parsed pattern. SEE ALSO
FcNameParse(3) FcConfigSubstitute(3) FcDefaultSubstitute(3) FcPatternPrint(3) FcPatternFormat(3) fc-cat(1) fc-cache(1) fc-list(1) fc- match(1) fc-query(1) fc-scan(1) The fontconfig user's guide, in HTML format: /usr/share/doc/fontconfig/fontconfig-user.html. AUTHOR
This manual page was updated by Behdad Esfahbod <behdad@behdad.org>. Apr 20, 2010 FC-PATTERN(1)
All times are GMT -4. The time now is 01:51 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy