Using sed to change values after a specific string
Hello I have a script that searches a file for a specific string and then changes the nth column after that string. I have searched online for how to do this with sed but have not seemed to find a solution that works for me. I am using bash.
Some background info:
- Currently I am using awk to do this successfully.
- I was informed that sed with --in place set would be faster
the awk command I use is as follows
What this does is finds the line where 'SITES' is written in the file (a label for that row) then changes the second element (column) of that row to mx (which is 50).
1. I want to know if its true that using sed will be faster (considering this is looped for thousands of files)
2. Also want to know how to implement with sed if thats the case. So far I have tried (and failed) the following:
I think there might be a misconception that sed is faster and from what I researched awk is the better option. The person who told me sed is faster has much more experience than me but I have a feeling he is incorrect.
Last edited by prodigious8; 10-21-2015 at 03:38 PM..
GNU sed version 4.1.4 on Windows XP SP3 from GnuWin32
I think that I've come across a seemingly simple text file change problem on a INI formatted file that I can't do with SED without side effects edge cases biting me. I've tried to think of various ways of doing this elegantly and quickly... (5 Replies)
using sed to replace a specific string on a specific line number using variables
this is where i am at
grep -v WARNING output | grep -v spawn | grep -v Passphrase | grep -v Authentication | grep -v '/sbin/tfadmin netguard -C'| grep -v 'NETWORK>' >> output.clean
grep -n Destination... (2 Replies)
Ok so all i'm trying to do here is output a file and change the color of a specific word. I can't use grep with color because I need all lines of the file not just lines that match the pattern.
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Hello,
I have this file.
aaa
port=1234
time
bbb
port=2233
name
ccc
port=4444
name
Is there any way with sed to change only the occurence of "port" which comes after section to have as output : (12 Replies)
Hi everyone,
I was wondering how could from a file where each row is separated by tabulations, the row values where are in blank replace them by a string or value.
My file has this form:
26/01/09 13:45:00 0 0
26/01/09 14:00:00 1495.601318 0
26/01/09 14:15:00 1495.601318 0 ... (4 Replies)
Dear All,
New to Linux/Unix OS, my Linux version is 2010 x86_64 x86_64 x86_64 GNU/Linux
As titled, I wonder if you can help to provide a solution to find and change an specific string in a file
The file include a lots of data in following configuration but might be various in... (3 Replies)
Hi,
I am writing a shell script where I want that # should be added in all those lines as the first character where the pattern matches.
file has lot of functions defined
a.sh
#!/bin/bash
fn a {
beautiful evening
sunny day
}
fn b {
}
fn c {
hello world .its a beautiful day
... (12 Replies)
Hello All of Master Script ,
i need help to solve my problem
before :
mount /dev/rdsk/c1t69d0s6 /dev/rdsk/c1t69d0s6 /vol/cl123/PURGE1 ufs
mount /dev/rdsk/c1t70d0s6 /dev/rdsk/c1t70d0s6 /vol/cl123/PURGE2 ufs
expected :
mount /dev/dsk/c1t69d0s6 /dev/rdsk/c1t69d0s6 /PURGE1 ufs
mount ... (3 Replies)
I am trying to use awk to change a specific string in a field, if it is found, to another value. In the tab-delimited file the text in bold in $3 contains the string 23, which is always right before a ., if it is present.
I am trying to change that string to X, keeping the formatting and the... (3 Replies)
Hi,
Could you please help me finding a way to replace a specific value in a text block when matching a key pattern ?
I got the keys and the values from a command similar to:
echo -e "key01 Nvalue01-1 Nvalue01-2 Nvalue01-3\nkey02 Nvalue02-1 Nvalue02-2 Nvalue02-3 \nkey03 Nvalue03-1... (2 Replies)
Discussion started by: alex2005
2 Replies
LEARN ABOUT MINIX
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)