Perl: How to read from a file, do regular expression and then replace the found regular expression
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
Code:
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print DESTINATION_FILE_2 "jessy\n";
chomp($_);
# print "$_ is $hash{$_}\n";
$line="CLIPPED_PIN_COUNT";
# print NEW_DESTINATION_FILE "$_\n";
#if ($_=~/^$line/)
if (/^CLIPPED_PIN_COUNT/)
{
print "original mathched:",$_,"\n";
$var=$hash{$line};
print "var is:",$var,"\n";
#Print out from tmptravl file
print "Obtain From tmptravl Fle:",$_,"\n";
#Split out
@field_new=split/:/,$_;
# print @field;
push @new_array_new, $field_new[$i];
print "field",$i,":",$field_new[$i],"\n";
$i ++;
push @new_array_new, $field_new[$i];
print "field",$i,":",$field_new[$i],"\n";
#Print out from original file
print "Obtain From Original File:",$var,"\n";
s/$_/$field_new[0]:$var/g;
print "After substituition:",$_,"\n";
print "-----------------------------------------\n";
print NEW_DESTINATION_FILE "$_\n";
# print DESTINATION_FILE,"s/$field_new[$1]/$var/";
#Subsititue original attribute to tmptravl attribue
close (DESTINATION_FILE);
close (NEW_DESTINATION_FILE);
}
}
Do I need to open two file handlers? My purpose is to overwrite the attribute i get from tmptravl.dat and write to new_tmptravl.dat? However, when I write to new_tmptravl.dat, only the new substitution is written in my new_tmptravl.dat? May I know what is the root cause for it?
Thanks.
Hi all,
I am trying to match a multi line string and return the matching string in one line. Here is the perl code that I wrote:
#!/usr/bin/perl
my $str='<title>My
title</title>';
if ($str =~ /(<title>)(+)(<\/title>)/ ){
print "$2\n";
}
It returns :
My
title
I want the... (3 Replies)
Hi all,
I have a file which contains 1000s of lines of text. I need to delete all lines with the words "Red" EXCEPT if the line also contains the word "GREEN"...
For example:
ThisIs some random text that should be red deleted
ThisIs some random text that should NOT be red deleted green
... (4 Replies)
Hello all,
I need to match the red expressions in the following lines :
MACRO_P+P-_scrambledServices_REM_PRC30.xml
MACRO_P+P-_scrambledServices_REM_RS636.xml
MACRO_P+P-_scrambledServices_REM_RS535.xml
and so on...
Can anyone give me a PERL regular expression to match those characters ?
... (5 Replies)
Hello,
I am trying to use perl LWP module to read and get a specfic URL page. The issue is that the URL ends with the data and time and time is not consistent it changes all the time. if anyone could help me how to write a regular expressin that would work in the LWP::UserAgent get function to... (0 Replies)
Hi I am doing something basic like...
if ($stringvariable =~ /have not typed/)
I have a little problem because the 'not' in the expression gets highlighted as a kind of a '!'..what am I supposed to do in this situation?
Thank you
---------- Post updated at 03:24 PM ----------... (1 Reply)
I would like to print 3 lines after a regular expression is found in the logfile. I'm using the following code:
grep -n "$reg_exp" file.txt |while read LINE ;do i=$(echo $LINE |cut -d':' -f1 ) ;sed -n "$i,$(($i+3))p" file.txt ;done
The above code things works fine,but sometimes gives erroneous... (3 Replies)
Hi ,
I have the below array
my @actionText = ("delivered to governor on 21/23/3345" , "deliver jllj" , "ram 2345/43");
When i am trying to grep the contents of array and if mathced substituting with the digitis or some date format from the element like below
my @action = grep { $_ =~... (7 Replies)
There are 2 strings as below.
$str1 = "41148,,,,,,,,,,,,,,,,,,,,,,,,";
$date = "TUE 08-28-2012";
The output should be as below
$str1 = "TUE 08-28-2012,,,,,,,,,,,,,,,,,,,,,,,,";
Could anyone please help with the perl regular expression or any other alternative? (3 Replies)
Discussion started by: giridhar276
3 Replies
LEARN ABOUT ULTRIX
grep
grep(1) General Commands Manual grep(1)Name
grep, egrep, fgrep - search file for regular expression
Syntax
grep [option...] expression [file...]
egrep [option...] [expression] [file...]
fgrep [option...] [strings] [file]
Description
Commands of the family search the input files (standard input default) for lines matching a pattern. Normally, each line found is copied
to the standard output.
The command patterns are limited regular expressions in the style of which uses a compact nondeterministic algorithm. The command patterns
are full regular expressions. The command uses a fast deterministic algorithm that sometimes needs exponential space. The command pat-
terns are fixed strings. The command is fast and compact.
In all cases the file name is shown if there is more than one input file. Take care when using the characters $ * [ ^ | ( ) and in the
expression because they are also meaningful to the Shell. It is safest to enclose the entire expression argument in single quotes ' '.
The command searches for lines that contain one of the (new line-separated) strings.
The command accepts extended regular expressions. In the following description `character' excludes new line:
A followed by a single character other than new line matches that character.
The character ^ matches the beginning of a line.
The character $ matches the end of a line.
A . (dot) 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 an * (asterisk) matches a sequence of 0 or more matches of the regular expression. A regular
expression followed by a + (plus) matches a sequence of 1 or more matches of the regular expression. A regular expression followed
by a ? (question mark) matches a sequence of 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 new line 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 the following: [], then *+?, then concatenation, then | and new
line.
Options-b Precedes each output line with its block number. This is sometimes useful in locating disk block numbers by context.
-c Produces count of matching lines only.
-e expression
Uses next argument as expression that begins with a minus (-).
-f file Takes regular expression (egrep) or string list (fgrep) from file.
-i Considers upper and lowercase letter identical in making comparisons and only).
-l Lists files with matching lines only once, separated by a new line.
-n Precedes each matching line with its line number.
-s Silent mode and nothing is printed (except error messages). This is useful for checking the error status (see DIAGNOSTICS).
-v Displays all lines that do not match specified expression.
-w Searches for an expression as for a word (as if surrounded by `<' and `>'). For further information, see only.
-x Prints exact lines matched in their entirety only).
Restrictions
Lines are limited to 256 characters; longer lines are truncated.
Diagnostics
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
See Alsoex(1), sed(1), sh(1)grep(1)
12-04-2011
