So I'm a bit confused about a regex pattern that should exist, but I can't really find any way to do it...
Let's say I want to match any lines that have a specific string, but I don't know the order of the letters but I know the length. Let's say it's 10 characters and begins with a V
Do I seriously have to do something like:
It could get worse if I knew there was a number in there somewhere... Is there no way to shorten this? I know there is a quantifier that I can add, something like
\{x,y\} but I've used it and it doesn't seem to work with letters?
Is there anyway to sum up saying that you're looking for 9 letters each could be a-z?
Last edited by Scrutinizer; 04-16-2016 at 12:52 AM..
Reason: code tags
having a look on the regex site I saw that characters can be search using hex values
http://www.regular-expressions.info/characters.html
So I try to use it whith grep to find a è on a string (octal Decimal Hexa : 350 232 E8) but it doesn't work
E.g.
/usr/bin/echo '\0350' | egrep '\xE8'
... (0 Replies)
Hello everybody,
I'd like to know how is it I should write a regex in unix to match a string not followed by another string (anywhere in the line).
To be more specific, I want to find lines where "drop table" is found, but not followed anywhere in the line by the character "&".
For... (3 Replies)
I want it to find lines that contain any number of capital letters before P
this is what I have tried
echo "AAAAAP" | grep 'P'
echo "AAAAAP" | grep '\{1\}P'
echo "AAAAAP" | grep '^*P'
But none of them seem to work, any help is much appreciated
thanks
Calypso (4 Replies)
Hello,
I'm working on unix with grep (GNU grep) 2.5.1. I'm going through some of the newer regex syntax using Regular Expression Reference - Advanced Syntax a guide.
ls -aLl /bin | grep "\(x\)"
Which works, just highlights 'x' where ever, when ever.
I'm trying to to get (?:) to work but... (4 Replies)
greetings citizens of Unix.com
I am perplexed with an issue.
The issue is trying to print the last 5 characters of a string in PERL.
Below are demonstrated my daft attempts at performing the forementioned task.
$row =~ m/^.*(.....)\s$/;
$row =~ m/\w{5}\s*$/i;$row =~... (3 Replies)
Hi all,
I have the following entries in a file:
Cause Indicators=80 90
Cause Indicators=80 90
Cause Indicators=82 90
Cause Indicators=82 90
Cause Indicators=82 90
The first 2 digits might change so I am after a sort of grep which could find any first 2 digits + the second 2,... (3 Replies)
Hello guys,
Here i am writing a script in bash to check for a valid URL from a file using regex
This is my input file
http://www.yahoo.commmmmm
http://www.google.com
https://www.gooogle.co
www.test6.co.in
www.gmail.com
www.google.co
htt://www.money.com
http://eeeess.google.com... (2 Replies)
Hi everyone,
I'm looking for a grep command to match the following pattern from a file:
<EGS>10234567<EGS>
I used this following command to do this:
grep -E '^<EGS>{8}<EGS>' test.txt
In output I got:
<EGS>10234567<EGS>
Till now it work, but if I add something at the end of the line... (2 Replies)
I am working on Sindhi: a perso-Arabic script and since it shares the Unicode-block with over 400 other languages, quite often the database contains characters which are not wanted: illegal characters.
I have identified the character set of Sindhi which is given below:
For clarity's sake, each... (8 Replies)
Discussion started by: gimley
8 Replies
LEARN ABOUT POSIX
regex
regex(1F) FMLI Commands regex(1F)NAME
regex - match patterns against a string
SYNOPSIS
regex [-e] [ -v "string"] [ pattern template] ... pattern [template]
DESCRIPTION
The regex command takes a string from the standard input, and a list of pattern / template pairs, and runs regex() to compare the string
against each pattern until there is a match. When a match occurs, regex writes the corresponding template to the standard output and
returns TRUE. The last (or only) pattern does not need a template. If that is the pattern that matches the string, the function simply
returns TRUE. If no match is found, regex returns FALSE.
The argument pattern is a regular expression of the form described in regex(). In most cases, pattern should be enclosed in single quotes
to turn off special meanings of characters. Note that only the final pattern in the list may lack a template.
The argument template may contain the strings $m0 through $m9, which will be expanded to the part of pattern enclosed in ( ... )$0 through
( ... )$9 constructs (see examples below). Note that if you use this feature, you must be sure to enclose template in single quotes so
that FMLI does not expand $m0 through $m9 at parse time. This feature gives regex much of the power of cut(1), paste(1), and grep(1), and
some of the capabilities of sed(1). If there is no template, the default is $m0$m1$m2$m3$m4$m5$m6$m7$m8$m9.
OPTIONS
The following options are supported:
-e Evaluates the corresponding template and writes the result to the standard output.
-v "string" Uses string instead of the standard input to match against patterns.
EXAMPLES
Example 1: Cutting letters out of a string
To cut the 4th through 8th letters out of a string (this example will output strin and return TRUE):
`regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`
Example 2: Validating input in a form
In a form, to validate input to field 5 as an integer:
valid=`regex -v "$F5" '^[0-9]+$'`
Example 3: Translating an environment variable in a form
In a form, to translate an environment variable which contains one of the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:
value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`
Note the use of the pattern '.*' to mean "anything else".
Example 4: Using backquoted expressions
In the example below, all three lines constitute a single backquoted expression. This expression, by itself, could be put in a menu defini-
tion file. Since backquoted expressions are expanded as they are parsed, and output from a backquoted expression (the cat command, in this
example) becomes part of the definition file being parsed, this expression would read /etc/passwd and make a dynamic menu of all the login
ids on the system.
`cat /etc/passwd | regex '^([^:]*)$0.*$' '
name=$m0
action=`message "$m0 is a user"`'`
DIAGNOSTICS
If none of the patterns match, regex returns FALSE, otherwise TRUE.
NOTES
Patterns and templates must often be enclosed in single quotes to turn off the special meanings of characters. Especially if you use the
$m0 through $m9 variables in the template, since FMLI will expand the variables (usually to "") before regex even sees them.
Single characters in character classes (inside []) must be listed before character ranges, otherwise they will not be recognized. For exam-
ple, [a-zA-Z_/] will not find underscores (_) or slashes (/), but [_/a-zA-Z] will.
The regular expressions accepted by regcmp differ slightly from other utilities (that is, sed, grep, awk, ed, and so forth).
regex with the -e option forces subsequent commands to be ignored. In other words, if a backquoted statement appears as follows:
`regex -e ...; command1; command2`
command1 and command2 would never be executed. However, dividing the expression into two:
`regex -e ...``command1; command2`
would yield the desired result.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO awk(1), cut(1), grep(1), paste(1), sed(1), regcmp(3C), attributes(5)SunOS 5.10 12 Jul 1999 regex(1F)