File functions grouped

1. File and Directory Manipulation

These functions are used to create, delete, move, or rename files and directories.

• fopen() — Opens a file or URL.
• fclose() — Closes an open file.
• rename() — Renames or moves a file or directory.
• unlink() — Deletes a file.
• rmdir() — Removes an empty directory.
• mkdir() — Creates a new directory.
• opendir() — Opens a directory.
• readdir() — Reads an entry from an open directory.
• closedir() — Closes an open directory.
• mkdir() — Creates a new directory.
• file_put_contents() — Writes data to a file (replaces the file if it already exists).
• file_get_contents() — Reads a file into a string.

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2. File and Directory Permissions

These functions are used for managing file and directory permissions (read/write/execute).

• chmod() — Changes the permissions of a file or directory.
• chown() — Changes the owner of a file or directory.
• chgrp() — Changes the group of a file or directory.
• fileperms() — Returns the permissions of a file.
• umask() — Sets the default file creation mask.

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3. File and Directory Properties

These functions are used to retrieve information about files and directories.

• file_exists() — Checks if a file or directory exists.
• is_file() — Checks if a given path is a regular file.
• is_dir() — Checks if a given path is a directory.
• is_readable() — Checks if a file or directory is readable.
• is_writable() — Checks if a file or directory is writable.
• is_executable() — Checks if a file or directory is executable.
• filemtime() — Returns the last modified time of a file.
• fileatime() — Returns the last access time of a file.
• filectime() — Returns the inode change time of a file.
• filesize() — Returns the size of a file.
• filetype() — Returns the type of a file (e.g., regular file, directory).
• stat() — Returns an array with file status information.
• fstat() — Returns the status of an open file.
• dirname() — Returns the directory name of a file path.
• basename() — Returns the filename from a file path.
• pathinfo() — Returns information about a file path.

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4. File Reading and Writing

These functions are used to read from and write to files.

• fread() — Reads a file.
• fwrite() — Writes to a file.
• fgets() — Reads a line from a file.
• fgetcsv() — Reads a CSV line from a file.
• file() — Reads a file into an array.
• file_get_contents() — Reads the entire content of a file into a string.
• file_put_contents() — Writes data to a file.
• readfile() — Reads a file and sends it directly to the output.
• fprintf() — Writes formatted data to a file.

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5. File Uploads

These functions are used for handling file uploads.

• move_uploaded_file() — Moves an uploaded file to a new location.
• is_uploaded_file() — Checks if a file was uploaded via HTTP POST.
• $_FILES — An array containing file upload information (used in conjunction with form file uploads).

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6. Directory Traversal

These functions are used to traverse directories, list files, and iterate over directory contents.

• opendir() — Opens a directory for reading.
• readdir() — Reads the next entry in an open directory.
• rewinddir() — Resets the directory pointer to the beginning of a directory.
• closedir() — Closes an open directory.
• scandir() — Returns a list of files and directories in a directory.
• glob() — Finds pathnames matching a pattern (e.g., *.txt).
• dir() — Creates a Directory object for traversing directories (object-oriented approach).

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7. File Locking

These functions are used for locking files to prevent other processes from modifying them.

• flock() — Acquires or releases a file lock.
• lockf() — Locks or unlocks a file (using file descriptor).
• fnctl() — Performs control operations on a file descriptor (Unix-based).

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8. Temporary Files and Directories

These functions are used to create temporary files and directories.

• tempnam() — Creates a temporary file with a unique name.
• tmpfile() — Creates a temporary file and returns a file handle.
• sys_get_temp_dir() — Returns the system's temporary directory path.

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9. File and Directory Traversal (Recursion)

These functions are used for recursively traversing directories and working with nested structures.

• RecursiveDirectoryIterator — Iterates over directories and subdirectories.
• RecursiveIteratorIterator — Provides a recursive iterator for iterating through nested directories.
• DirectoryIterator — Iterates over files and directories in a directory.

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10. Compression and Archiving

These functions help with creating or extracting compressed files and archives.

• gzopen() — Opens a gzipped file for reading or writing.
• gzread() — Reads from a gzipped file.
• gzwrite() — Writes to a gzipped file.
• gzclose() — Closes a gzipped file.
• zip_open() — Opens a ZIP archive.
• zip_read() — Reads a file from a ZIP archive.
• zip_close() — Closes a ZIP archive.
• tar() — Creates a TAR archive.

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11. Miscellaneous Functions

Other miscellaneous filesystem-related functions:

• disk_free_space() — Returns the free space available on a disk or directory.
• disk_total_space() — Returns the total space on a disk or directory.
• realpath() — Returns the absolute path of a file or directory.
• clearstatcache() — Clears the file status cache, used after modifying file information.
• file_exists() — Checks if a file or directory exists.
• touch() — Sets the access time and modification time of a file.