It removes the line completely, and doesn't even leave the newline. If you require the newline to be preserved, it's a bit harder.
It's not too tough to generate a proper regular expression, per se, but it tends to be a bit ugly.
This is untested, and intended merely as a proof of concept. I probably forgot one or two special characters which need to be backslash-escaped. (Hint: remove the final part of the pipeline to see the generated script.)
I have got a question. How to do this? I mean AND expression in regex.
List all the files in current directory that do not contain the words use AND take.
Thx.:p (15 Replies)
here is my prob ..
i have a very large text files and i need to locate specific lines, copy them and then replace a single word in the replaced text
example
find all lines that contain '/etc', copy the line immediately below (not at the end of the file) and then replace '/etc' with '/root'... (1 Reply)
Hi all,
I am looking to create words from a sentence which adhere to a custom search pattern from my website:
Example:
! +! / += ~
where the terms ! = not, +! = AND NOT, += - and equals and ~ = can be like....
Now here is the issue...i want to split a sentence like the one above on... (1 Reply)
Hi,
I am trying to write a script which will modify a given account's settings by searching for a line in a file and then replacing the line after it. Here is a portion of my input file:
type=friend
username=0002
secret=password
host=dynamic
dtmfmode=rfc2833
mailbox=0002
context=sip... (2 Replies)
I am trying to write a find and replace script with AWK and I can't seem to get it to work. I need it to find this exact string *P*: and replace the P with a T or just replcare the whole thing with *T*:.
this is what I have tried
awk 'BEGIN {gsub(/\*P*:/,"\*T*:"); print}' ${INFILE} >... (4 Replies)
Hello,
I am trying to grep my log files for ORA errors, except ORA-00001.
I have tried:
grep 'ORA*!(-00001)' *.log
but it is not working.
Any help will be much appreciated.
Thank you. (5 Replies)
I am trying to grep the following line in a file using a bash shell:
(..)
admin1::14959::::::
(..)
It works with the following expression (as expected)
# cat file | grep ^*::
admin1::14959::::::
but it does not work with (not expected)
# cat /etc/shadow | grep ^+::
I assume the... (2 Replies)
Hi!
I'm looking for a simple script, especially a one liner script in tcsh or bash
that will emulate the find/replace in all text apps.
I want to change all uppercase caracters to Title word (in wich only the first caracter is UpperCase and the rest is lowercase)
I can use sed command, but... (2 Replies)
Hello all!
This is my first post and I'm very new to programming. I would like help creating a simple perl or bash script that I will be using in my work as a junior bioinformatician.
Essentially, I would like to take a tab-delimted or .csv text with 3 columns and write them to a "3D" matrix:
... (16 Replies)
Hi !
Before trying to write a code, is there any program or code that generates all the combinations of strings that simple awk regex can match.
By "simple regex" I mean let's say without "+", "*", and with a limited number of characters (e.g. from "1" to "5").
e.g:
input:
34?5
output:... (9 Replies)
Discussion started by: beca123456
9 Replies
LEARN ABOUT BSD
egrep
GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output. Grep patterns are limited regular expressions in the style of ex(1); it uses a compact nondeterministic
algorithm. Egrep patterns are full regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space.
Fgrep patterns are fixed strings; it is fast and compact. The following options are recognized.
-v All lines but those matching are printed.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its relative line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-i The case of letters is ignored in making comparisons -- that is, upper and lower case are considered identical. This applies to
grep and fgrep only.
-s Silent mode. Nothing is printed (except error messages). This is useful for checking the error status.
-w The expression is searched for as a word (as if surrounded by `<' and `>', see ex(1).) (grep only)
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
In all cases the file name is shown if there is more than one input file. Care should be taken when using the characters $ * [ ^ | ( ) and
in the expression as they are also meaningful to the Shell. It is safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character other than newline matches that character.
The character ^ matches the beginning of a line.
The character $ matches the end of a line.
A . (period) matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by an * (asterisk) matches a sequence of 0 or more matches of the regular expression. A regular
expression followed by a + (plus) matches a sequence of 1 or more matches of the regular expression. A regular expression followed
by a ? (question mark) matches a sequence of 0 or 1 matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
SEE ALSO ex(1), sed(1), sh(1)DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files.
BUGS
Lines are limited to 256 characters; longer lines are truncated.
4th Berkeley Distribution April 29, 1985 GREP(1)