Difference between pear and PECL and between PCRE and POSIX

/************* By garcon1986 *******************/

 

Pear
(PhP extension and application
Repository) PHP extension and application library.

 

Pear is a "framework and Release System for reusable PHP components ". Pear can download, install, upgrade, and delete PHP scripts.
When using the pear package, you don't have to worry about the location of the script or how to find them, and the command line interface (CLI) extension is also easy to use.
Pear is a community-driven PHP project. The officially released PHP contains pear.

PECL
(PHP
The PHP extension community library is an open and packaged PHP extension library repository. The pear package manager can be used to download and install the PECL module.

Difference between pear and PECL:

 

Pear: it is an extension code package of PHP. All extensions are in the form of PHP code. They are powerful and easy to install, and can even be used after modification. You must include it in the code before using it.

PECL: it is a standard extension of PHP and can supplement the functions required in actual development. All extensions need to be installed and appear in the form of DLL in windows. In Linux, it needs to be compiled separately. It is written in C language according to official PHP standards. Although the source code is open, the source code cannot be changed at will.

 

 

The most direct expression: pear is the upper-layer extension of PHP, and PECL is the underlying extension of PHP.

Both methods provide ready-made functions or classes for specific applications, which are essentially the same.

 

Regular Expression
:

 

PCRE
: Perl Compatible Regular Expression functions (Perl Compatible Regular Expression)

Function:

• Preg_filter
  -Perform a regular expression search and replace
• Preg_grep
  -Return array entries that match the pattern
• Preg_last_error
  -Returns the error code of the last PCRE RegEx execution
• Preg_match_all
  -Perform a global regular expression match
• Preg_match
  -Perform a regular expression match
• Preg_quote
  -Quote Regular Expression characters
• Preg_replace_callback
  -Perform a regular expression search and replace using a callback
• Preg_replace
  -Perform a regular expression search and replace
• Preg_split
  -Split string by a regular expression

POSIX
:

Function:

• Posix_access
  -Determine accessibility of a file
• Posix_ctermid
  -Get path name of controlling Terminal
• Posix_errno
  -Alias of posix_get_last_error
• Posix_get_last_error
  -Retrieve the error number set by the last POSIX function that failed
• Posix_getcwd
  -Pathname of Current Directory
• Posix_getegid
  -Return the valid tive group ID of the current process
• Posix_geteuid
  -Return the valid user ID of the current process
• Posix_getgid
  -Return the real group ID of the current process
• Posix_getgrgid
  -Return info about a group by group ID
• Posix_getgrnam
  -Return info about a group by name
• Posix_getgroups
  -Return the group set of the current process
• Posix_getlogin
  -Return Login Name
• Posix_getpgid
  -Get Process Group ID for Job Control
• Posix_getpgrp
  -Return the current process Group Identifier
• Posix_getpid
  -Return the current process identifier
• Posix_getppid
  -Return the parent process identifier
• Posix_getpwnam
  -Return info about a user by username
• Posix_getpwuid
  -Return info about a user by user ID
• Posix_getrlimit
  -Return info about system resource limits
• Posix_getsid
  -Get the current SID of the process
• Posix_getuid
  -Return the real User ID of the current process
• Posix_initgroups
  -Calculate the Group access list
• Posix_isatty
  -Determine if a file descriptor is an interactive Terminal
• Posix_kill
  -Send a signal to a process
• Posix_mkfifo
  -Create a FIFO special file (a named pipe)
• Posix_mknod
  -Create a special or ordinary file (posix.1)
• Posix_setegid
  -Set the valid tive gid of the current process
• Posix_seteuid
  -Set the valid uid of the current process
• Posix_setgid
  -Set the GID of the current process
• Posix_setpgid
  -Set Process Group ID for Job Control
• Posix_setsid
  -Make the current process a session leader
• Posix_setuid
  -Set the UID of the current process
• Posix_strerror
  -Retrieve the system error message associated with the given errno
• Posix_times
  -Get process times
• Posix_ttyname
  -Determine terminal device name
• Posix_uname
  -Get system name

PCRE is more powerful than POSIX.