If your shell supports substring expansion (${text:$n:1}), then you can probably replace all of that with a much simpler, pattern substitution alternative:
Regards,
Alister
Hi everybody!
Im not good in scripting and I need a script to take all the files with spaces in their names and change it to underscores.
alice cooper.mp3 >> alice_cooper.mp3
Thanks in advance. (2 Replies)
Greetings,
I have a bunch of music files that I want to strip the underscores out, and leave only spaces. All that I've found on the web is how to add underscores to files that have spaces, and reversing the "tr" command does not make a difference.
Here is how to convert spaces to... (6 Replies)
Hi,
Here is my question,
I need to extract string between two underscores from the filename
for example, filename is
atmos_8xdaily_instant_300x300_1_12.nc
what I want to extract is 300x300.
There are many such files in my directory, so I guess the code should be like:
for file... (7 Replies)
Hi Friends,
I'm a great fan of this forum... it has helped me tone my skills in shell scripting. I have a challenge here, which I'm sure you guys would help me in achieving...
File A has a list of job ids and I need to compare this with the File B (*.log) and File C (extend *.log) and copy... (6 Replies)
Hello,
I have a file, inputs.list that contain prefixes to files that are inputs for a program
inputs.list
A
B
C
D
E
...
My files are of the format A_1, A_2, B_1, B_2 and so on. I am planning to run a shell script that takes each line from the above file and feed it to the runProg.sh... (3 Replies)
Hi,
I need to compare 2 text files with around 60000 rows and 1 column. I need to compare these and write the mismatch data to 3rd file.
File1 - file2 = file3
wc -l file1.txt
58112
wc -l file2.txt
55260
head -5 file1.txt
101214200123
101214700300
101250030067
101214100500... (10 Replies)
All, I've searched and haven't found a solution for my particular issue.
I have a file with lines of data that contain varying amounts of underscores imbedded. But all the strings have a final underscore and an interface name:
dmk_hcn_dalian2.XXXX.XXX.XX.COM_Se0/0/0... (4 Replies)
I have a comma delimited file of major codes and descriptions. I want to replace all occurrences of spaces with underscores up to the first comma (only in the first field), but not replace spaces following the comma. For instance I have the following snippet of the file:
EK ED,Elementary and... (7 Replies)
Shell script logic
Hi
I have 2 input files like with file 1 content as (file1)
"BRGTEST-242" a.txt "BRGTEST-240" a.txt "BRGTEST-219" e.txt
File 2 contents as fle(2)
"BRGTEST-244" a.txt "BRGTEST-244" b.txt "BRGTEST-231" c.txt "BRGTEST-231" d.txt "BRGTEST-221" e.txt
I want to get... (22 Replies)
Discussion started by: pottic
22 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)