grep will always output the whole line, no matter how small the part you actually searched for.
That said, the "memory" you're referring to are called "capturing groups", and can even be nested. If, for example, you take the Perl expression
You'd have "a test." in $1, "a" in $2, and "test." in $3
How can i create a regular expression which can detect a new line charcter followed by a special character say * and replace these both by a string of zero length?
Eg:
Input File san.txt
hello
hi ... (6 Replies)
how to find for a file whose name has all characters in uppercase after 'project'?
I tried this:
find . -name 'project**.pdf'
./projectABC.pdf
./projectABC123.pdf
I want only ./projectABC.pdf
What is the regular expression that correponds to "all characters are capital"?
thanks (8 Replies)
I have a flat file with the following drug names
Nutropin AQ 20mg PEN Cart 2ml
Norditropin Cart 15mg/1.5ml
I have to extract digits that are before mg i.e 20 and 15 ; how to do this using regular expressions
Thanks
ram (1 Reply)
In regular expressions with grep(or egrep), ^ works if we want something in starting of line..but what if we write ^^^ or ^ for pattern matching??..Hope u all r familiar with regular expressions for pattern matching.. (1 Reply)
#!/usr/bin/perl
$word = "one last challenge";
if ( $word =~ /^(\w+).*\s(\w+)$/ )
{
print "$1";
print "\n";
print "$2";
}
The output shows that "$1" is with result one and "$2" is with result challenge. I am confused about how this pattern match expression works step by step. I... (8 Replies)
what elements does " /^/ " match?
I did the test which indicates that it matches single lowercase character like 'a','b' etc. and '1','2' etc.
But I really confused with that. Because, "/^abc/" matches strings like "abcedf" or "abcddddee".
So, what does caret ^ really mean?
Any response... (2 Replies)
I have a file that I'm trying to find all the cases of phone number extensions and deleting them. So input file looks like:
abc
x93825
def
13234
x52673
hello
output looks like:
abc
def
13234
hello
Basically delete lines that have 5 numbers following "x". I tried: x\(4) but it... (7 Replies)
I need to pick a part of string lets stay started with specific character and end with specific character to replace using sed command
the line is like this:my audio book 71-skhdfon1dufgjhgf8.wav'
I want to move the characters beginning with - end before.
I have different files with random... (2 Replies)
Discussion started by: XP_2600
2 Replies
LEARN ABOUT OSX
trim
textutil::trim(n) Text and string utilities, macro processing textutil::trim(n)
__________________________________________________________________________________________________________________________________________________NAME
textutil::trim - Procedures to trim strings
SYNOPSIS
package require Tcl 8.2
package require textutil::trim ?0.7?
::textutil::trim::trim string ?regexp?
::textutil::trim::trimleft string ?regexp?
::textutil::trim::trimright string ?regexp?
::textutil::trim::trimPrefix string prefix
::textutil::trim::trimEmptyHeading string
_________________________________________________________________DESCRIPTION
The package textutil::trim provides commands that trim strings using arbitrary regular expressions.
The complete set of procedures is described below.
::textutil::trim::trim string ?regexp?
Remove in string any leading and trailing substring according to the regular expression regexp and return the result as a new
string. This is done for all lines in the string, that is any substring between 2 newline chars, or between the beginning of the
string and a newline, or between a newline and the end of the string, or, if the string contain no newline, between the beginning
and the end of the string. The regular expression regexp defaults to "[ \t]+".
::textutil::trim::trimleft string ?regexp?
Remove in string any leading substring according to the regular expression regexp and return the result as a new string. This apply
on any line in the string, that is any substring between 2 newline chars, or between the beginning of the string and a newline, or
between a newline and the end of the string, or, if the string contain no newline, between the beginning and the end of the string.
The regular expression regexp defaults to "[ \t]+".
::textutil::trim::trimright string ?regexp?
Remove in string any trailing substring according to the regular expression regexp and return the result as a new string. This apply
on any line in the string, that is any substring between 2 newline chars, or between the beginning of the string and a newline, or
between a newline and the end of the string, or, if the string contain no newline, between the beginning and the end of the string.
The regular expression regexp defaults to "[ \t]+".
::textutil::trim::trimPrefix string prefix
Removes the prefix from the beginning of string and returns the result. The string is left unchanged if it doesn't have prefix at
its beginning.
::textutil::trim::trimEmptyHeading string
Looks for empty lines (including lines consisting of only whitespace) at the beginning of the string and removes it. The modified
string is returned as the result of the command.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category textutil
of the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for
either package and/or documentation.
SEE ALSO
regexp(n), split(n), string(n)
KEYWORDS
prefix, regular expression, string, trimming
CATEGORY
Text processing
textutil 0.7 textutil::trim(n)