I am writing a c++ program that has many calls of pow(input,2). I now realize that this is slowing down the program and these all should be input * input for greater speed.
There should be a simple way of doing this replacement throughout my file with awk, but I am not very familiar with awk.... (2 Replies)
Hi,
I have a file having around 30 records. Each record has 5 fields delimited by PIPE. Few records in the file having Junk characters in the field2 and field4.
I found the junk charcter and I tested it and replace the junk with space with the command below
perl -i -p -e "s/\x00/ /g"... (1 Reply)
Dear All,
I have file with 4 columns:
1 AA 0 21
2 BB 0 31
3 AA 0 21
4 CC 0 41
I would like to find the duplicate record based on column 2 and replace the 4th column of the duplicate by a new value. So, the output will be:
1 AA 0 21
2 BB 0 31
3 AA 0 -21
4 CC 0 41
Any suggestions... (3 Replies)
Hi,
I need to search for source path in file2 , as per file1 and if found get the next line and take the field value and put it in URL value of file1.
In file1, NF is not same for all the lines.
file1:
<type source="/home/USER/Desktop" Dest="/home/USER/DIR1/Desktop" URL="ssh/path"/>
<type... (8 Replies)
I have 2 files A.txt and B.txt
A.txt 3 fields and separate by a comma
some,thing,florida
any1,thing1,california
some2,thing2,dallas
just,fun,kansas
B.txt has 8 fields and separate by a comma
what,ever,florida-state,,,,,,
some,one,dallas_state,,,,,,
You will see 3rd fields are the... (5 Replies)
Hi
I would like to apply this gawk command:
gawk '{$0=gensub(/\y+\y/,"","g"); print}' file
not to the whole $0 but just to the part of $0 that is between:
(a number)"> and </mrk>
Is it possible?
thanks for your help. (4 Replies)
Hi,
I have an input file with below data and rules file to apply search and replace by each field in the input based on exact value or pattern.
Could you please help me with unix script to read input file and rules file and then create the output and reject files based on the rules file.
Input... (13 Replies)
Hi there,
First of all this is my first post here. Thank you in advance for your help.
What I am trying to do is the following. I have a text file where each field of each row is separated by a tabulator.
Looks like this:
ATOM 1 N HSE A 26 3.033 -10.429 -2.262 1.00 17.07 ... (8 Replies)
Hello friends,
I have huge file with many sets where each "set" has few lines and each set always begins with "Set" in Sq brackets as shown above.
# cat file1 (2 Replies)
Hi,
I have a text file which looks like this
a.txt
A,12,Apple,Red
B,33,Banana,Yellow
C,66,Sky,Blue
I need to search for a particular field(s) in particular column(s) and for that matching line need to replace the nth column.
Sample scenario 1:
Search for 66 in second field and Sky in... (5 Replies)
Discussion started by: wahi80
5 Replies
LEARN ABOUT PHP
preg_replace_callback
PREG_REPLACE_CALLBACK(3) 1 PREG_REPLACE_CALLBACK(3)preg_replace_callback - Perform a regular expression search and replace using a callbackSYNOPSIS
mixed preg_replace_callback (mixed $pattern, callable $callback, mixed $subject, [int $limit = -1], [int &$count])
DESCRIPTION
The behavior of this function is almost identical to preg_replace(3), except for the fact that instead of $replacement parameter, one
should specify a $callback.
PARAMETERS
o $pattern
- The pattern to search for. It can be either a string or an array with strings.
o $callback
- A callback that will be called and passed an array of matched elements in the $subject string. The callback should return the
replacement string. This is the callback signature:
string handler (array $matches) You'll often need the $callback function for a preg_replace_callback(3) in just one place. In
this case you can use an anonymous function to declare the callback within the call to preg_replace_callback(3). By doing it this
way you have all information for the call in one place and do not clutter the function namespace with a callback function's name
not used anywhere else.
Example #1
preg_replace_callback(3) and anonymous function
<?php
/* a unix-style command line filter to convert uppercase
* letters at the beginning of paragraphs to lowercase */
$fp = fopen("php://stdin", "r") or die("can't read stdin");
while (!feof($fp)) {
$line = fgets($fp);
$line = preg_replace_callback(
'|<p>s*w|',
function ($matches) {
return strtolower($matches[0]);
},
$line
);
echo $line;
}
fclose($fp);
?>
o $subject
- The string or an array with strings to search and replace.
o $limit
- The maximum possible replacements for each pattern in each $subject string. Defaults to -1 (no limit).
o $count
- If specified, this variable will be filled with the number of replacements done.
RETURN VALUES preg_replace_callback(3) returns an array if the $subject parameter is an array, or a string otherwise. On errors the return value is NULL
If matches are found, the new subject will be returned, otherwise $subject will be returned unchanged.
CHANGELOG
+--------+---------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------+
| 5.1.0 | |
| | |
| | The $count parameter was added |
| | |
+--------+---------------------------------+
EXAMPLES
Example #2
preg_replace_callback(3) example
<?php
// this text was used in 2002
// we want to get this up to date for 2003
$text = "April fools day is 04/01/2002
";
$text.= "Last christmas was 12/24/2001
";
// the callback function
function next_year($matches)
{
// as usual: $matches[0] is the complete match
// $matches[1] the match for the first subpattern
// enclosed in '(...)' and so on
return $matches[1].($matches[2]+1);
}
echo preg_replace_callback(
"|(d{2}/d{2}/)(d{4})|",
"next_year",
$text);
?>
The above example will output:
April fools day is 04/01/2003
Last christmas was 12/24/2002
Example #3
preg_replace_callback(3) using recursive structure to handle encapsulated BB code
<?php
$input = "plain [indent] deep [indent] deeper [/indent] deep [/indent] plain";
function parseTagsRecursive($input)
{
$regex = '#[indent]((?:[^[]|[(?!/?indent])|(?R))+)[/indent]#';
if (is_array($input)) {
$input = '<div style="margin-left: 10px">'.$input[1].'</div>';
}
return preg_replace_callback($regex, 'parseTagsRecursive', $input);
}
$output = parseTagsRecursive($input);
echo $output;
?>
SEE ALSO
PCRE Patterns, preg_quote(3), preg_replace(3), preg_last_error(3), Anonymous functions, information about the callback type.
PHP Documentation Group PREG_REPLACE_CALLBACK(3)