web developers guide: 2011-06-16

php - chgrp

Changes file group

bool chgrp ( string $filename, mixed $group )

Attempts to change the group of the file filename to group.
Only the superuser may change the group of a file arbitrarily; other users may change the group of a file to any group of which that user is a member.

Parameters

filename: Path to the file.
group: A group name or number.

Return Values

Returns TRUE on success or FALSE on failure.

php - checkdnsrr

Check DNS records corresponding to a given Internet host name or IP address

Description

int checkdnsrr ( string $host [, string $type] )
Searches DNS for records of type type corresponding to host.

Parameters

host: host may either be the IP address in dotted-quad notation or the host name.
type: type may be any one of: A, MX, NS, SOA, PTR, CNAME, AAAA, A6, SRV, NAPTR, TXT or ANY. The default is MX.

Return Values

Returns TRUE if any records are found; returns FALSE if no records were found or if an error occurred.

php - checkdate

Validate a Gregorian date

Description

bool checkdate ( int $month, int $day, int $year )
Checks the validity of the date formed by the arguments. A date is considered valid if each parameter is properly defined.

Parameters

month: The month is between 1 and 12 inclusive.
day: The day is within the allowed number of days for the given month. Leap years are taken into consideration.
year: The year is between 1 and 32767 inclusive.

Return Values

Returns TRUE if the date given is valid; otherwise returns FALSE.

Examples

Example 430. checkdate() example

<?php

var_dump(checkdate(12, 31, 2000));

var_dump(checkdate(2, 29, 2001));

?>

The above example will output:

bool(true)
bool(false)

php - chdir

Change directory

Description

bool chdir ( string $directory )
Changes PHP's current directory to directory.

Parameters

directory: The new current directory

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example 494. chdir() example

<?php



// current directory

echo getcwd() . "\n";

chdir('public_html');



// current directory

echo getcwd() . "\n";

?>

The above example will output something similar to:

/home/vincent
/home/vincent/public_html

php - ceil

Round fractions up

Description

float ceil ( float $value )
Returns the next highest integer value by rounding up value if necessary.

Parameters

value: The value to round

Return Values

value rounded up to the next highest integer. The return value of ceil() is still of type float as the value range of float is usually bigger than that of integer.

Examples

Example 1125. ceil() example

<?php



echo ceil(4.3);    // 5

echo ceil(9.999); // 10
echo ceil(-3.14); // -3

?>