A simple find and replace without using any regex (bash)
Hi,
I need to do an exact find and replace (I don't want to use regular expressions because the input comes from user). I want to find a line that matches the user's input text and replace it with an empty string.
For example, let's say the user enters I love "Unix" and the contents of the file where I want to do find and replace is this:
Now I want to replace the line I love "Unix" with empty string. And I want to leave the remaining lines like I said I love "Unix" and I love "Unix" a lot as is. The double-quotes are intentional.
Which Unix utility can do this? An example would be great! I searched and found that sed is something close what I am looking for, but it takes a regular expression. Because the input string is coming from the user, it's tough for me to generate a regular expression for that. Any other ways?
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 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)