10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi
Ilove unix and alwyas trying to to learn unix,but i am weak in using regular expressions.can you please give me a littel brief discription that how can i understand them and how to use .your response could lead a great hand in my unix love. (1 Reply)
Discussion started by: manoj attri
1 Replies
2. Shell Programming and Scripting
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)
Discussion started by: pxalpine
7 Replies
3. Shell Programming and Scripting
need a regex that matches when a number has a zero (0) at the end of it
so like
10
20
120
30
330
1000
and so on (6 Replies)
Discussion started by: linuxkid
6 Replies
4. Shell Programming and Scripting
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)
Discussion started by: DavidHe
2 Replies
5. Shell Programming and Scripting
#!/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)
Discussion started by: DavidHe
8 Replies
6. UNIX for Advanced & Expert Users
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)
Discussion started by: ramky79
1 Replies
7. UNIX for Advanced & Expert Users
Hi,
below is a piece of code written by my predecessor at work.
I'm kind of a newbie and am trying to figure out all the regular expressions in this piece of code.
It is really a tough time for me to figure out all the regular expressions.
Please shed some light on the regular expressions... (3 Replies)
Discussion started by: ramky79
3 Replies
8. UNIX for Dummies Questions & Answers
Hi Gurus,
I need help with regular expressions. I want to create a regular expression which will take only alpha-numeric characters for 7 characters long and will throw out an error if longer than that.
i tried various combinations but couldn't get it, please help me how to get it guys.
... (2 Replies)
Discussion started by: ragha81
2 Replies
9. Shell Programming and Scripting
I have following content in the file
CancelPolicyMultiLingual3=U|PC3|EN
RestaurantInfoCode1=U|restID1|1
.....
I am trying to use following matching extression
\|(+)
to get this
PC3|EN
restID1|1
Obviously it does not work.
Any ideas? (13 Replies)
Discussion started by: arushunter
13 Replies
10. Shell Programming and Scripting
I'm trying to parse RichText to XML. I want to be able to capture everything between the '/par' tag in the RTF but not include the tag itself. So far all I have is this, '.*?\\par' but it leaves '\par' at the end of it. Any suggestions? (1 Reply)
Discussion started by: AresMedia
1 Replies
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)
