Factoring out the common string chr:
Try to avoid regex's if you can, to improve efficiency. Also, if you happen to know, to a reasonable extent, the frequency of occurrence of those strings, you could use simple string comparisons (with the proper order of comparisons) with the short-circuit logical OR (||) operator.
Last edited by elixir_sinari; 03-24-2013 at 01:13 PM..
This User Gave Thanks to elixir_sinari For This Post:
I have a varable(var1) in a AWK script that contain data in the following format
-
I need to extract timestamp,priority and log message.I can extract these by using split function but i don't want to use it, since i want to extract it in one go. I have some difficulties in doing it using... (3 Replies)
Ive got a file with words and also numbers.
Bla BLA
10 10
11 29
12 89
13 35
And i need to change "10,29,89,25" and also remove anything that contains actually words... (4 Replies)
I can print a line with an expression using this:
awk '/regex/'
I can print the line immediately before an expression using this:
awk '/regex/{print x};{x=$0}'
How do I print the line immediately before and then the line with the expression? (2 Replies)
Hello Experts,
Please help me to cope with the following problem
I ve patterens like
Input
Noptx(5) // remain the same
-*Nop(3);
Nop(9);
--Nop(8); // remain the same d3
**---Nop(7); //remain the same d3
**---Nop(7);
*--Nop(6);
--**Nop(5);
-Nop(4);
Nop(3);
- represents a space... (2 Replies)
Hi,
I have a string like this-->"After Executing service For 10 Request"
in this string i need to extract "10".
the contents of the string is variable and "10" appears before "For" and after "Request" i.e, in this format "For x Request"
I need to extract the value of x. How to do this in AWK?... (10 Replies)
I have a file "fwcsales_filenames.txt" which has a list of file names that are supposed to be copied to another directory. In addition to that, I am trying to extract the date part and write to the log.
I am getting the regular expression error when trying to strip the date part using the "ll"... (1 Reply)
Hello world,
I was wondering if there is a nicer way to write the following code (in AWK):
awk '
FNR==NR&&$1~/^m$/{tok1=1}
FNR==NR&&$1~/^m10$/{tok1=1}
' my_file
In fact, it looks for m2, m4, m6, m8 and m10 and then return a positive flag. The problem is how to define 10 thanks... (3 Replies)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
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... (1 Reply)
Hi,
I have a file with two fields in it as shown below
14,30
28,30
16,30
22,30
21,30
3,30
Fields are separated by comma ",".
I've been trying to validate the file based on the condition "each field must be a numeric value"
I am using HP-UX OS.
I have tried the following awk... (4 Replies)
Hi All,
I would like to search a regular expression by passing as an i/p variableto AWK.
For Example ::
162.111.101.209.9516
162.111.101.209.41891
162.111.101.209.9516
162.111.101.209.9517
162.111.101.209.41918
162.111.101.209.9517
162.111.101.209.41937
162.111.101.209.41951... (7 Replies)
Discussion started by: Girish19
7 Replies
LEARN ABOUT PLAN9
regexp
REGEXP(6) Games Manual REGEXP(6)NAME
regexp - regular expression notation
DESCRIPTION
A regular expression specifies a set of strings of characters. A member of this set of strings is said to be matched by the regular
expression. In many applications a delimiter character, commonly bounds a regular expression. In the following specification for regular
expressions the word `character' means any character (rune) but newline.
The syntax for a regular expression e0 is
e3: literal | charclass | '.' | '^' | '$' | '(' e0 ')'
e2: e3
| e2 REP
REP: '*' | '+' | '?'
e1: e2
| e1 e2
e0: e1
| e0 '|' e1
A literal is any non-metacharacter, or a metacharacter (one of .*+?[]()|^$), or the delimiter preceded by
A charclass is a nonempty string s bracketed [s] (or [^s]); it matches any character in (or not in) s. A negated character class never
matches newline. A substring a-b, with a and b in ascending order, stands for the inclusive range of characters between a and b. In s,
the metacharacters an initial and the regular expression delimiter must be preceded by a other metacharacters have no special meaning and
may appear unescaped.
A matches any character.
A matches the beginning of a line; matches the end of the line.
The REP operators match zero or more (*), one or more (+), zero or one (?), instances respectively of the preceding regular expression e2.
A concatenated regular expression, e1e2, matches a match to e1 followed by a match to e2.
An alternative regular expression, e0|e1, matches either a match to e0 or a match to e1.
A match to any part of a regular expression extends as far as possible without preventing a match to the remainder of the regular expres-
sion.
SEE ALSO awk(1), ed(1), sam(1), sed(1), regexp(2)REGEXP(6)