Hi
I have a file with data arranged into columns. The first column is the chromosome name.
When I use grep to subset only rows with chr1, I get chr1 but also chr10, chr11,..
How do I get only rows with chr1?
grep chr1 filein > fileout
head fileout
chr1 59757841
chr11 108258691 ... (2 Replies)
Hi,
I'm struggling with a regex that would match a 'b' that follows an 'a' and is at the end of a string of non-white characters. For example:
Line 1: aba abab b abb aab bab baa
I can find the right strings but I'm lacking knowledge of how to "discard" the bits that precede bs.... (2 Replies)
Hi all,
any idea how to match the following:
char*<no or any string or space> buf and
char *<no or any string or space> buf
i need to capture the buf characters too.
currently i need two checks to cover this:
#search char* <any string> buf or char *<any string> buf
@noarray =... (2 Replies)
Hi all,
I am looking for a regex syntax to match repeated appearance. Likes,
']+]+' matches for string '65A SOME MORE AND 78B'
Now, this gets messy if I need to extract all such repeated appearance. I don't want to write ] four or five times for matching repeated appearance.
Thanks in... (2 Replies)
I am trying to match a similar line using grep with regular expression
the line is
/remote/mac/pbbbb/abc/def/hij/hop/include/abc/tif/element/test/testfiles/Office.cpp:57: const OfficeType& getType().get() const;
I just need to extract the bold characters using grep with regular expression.... (5 Replies)
hi everyone
suppose we have two scenario
echo ABCD | grep \{4\}
DATE
echo SYSDATE | grep \{4\}
SYSDATE
i want to match the string of four length only please help (5 Replies)
I've found this script which seems very promising to solve my issue:
To search and replace many different database passwords in many different (.php, .pl, .cgi, etc.) files across my filesystem.
The passwords may or may not be contained within quotes, single quotes, etc.
#!/bin/bash... (4 Replies)
echo 20110101 | awk '{ print match($0,/^((17||18||19||20)|)-*(|0|1)-*(|0||3)$/))
I am getting a match for the above, where as it shouldn't, as there is no hyphen in the echoed date.
Another question is what is the difference between || and | in the above statement (4 Replies)
Hi
I'd like to add the newline:
\tuser: nobody", or "<TAB>user: nobody
to all files named:
docker-compose.ymlin subfolders of pwd with names beginning with 10-20.
Within these files, I'd like to find the line (there'll only be one) containing:
command: celery workerNOTE: As far as... (2 Replies)
Discussion started by: duncanbetts
2 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)