PHP built-in functions

Abs: obtain the absolute value.
Acos: returns the arc cosine.
Ada_afetch: gets the back column of the database.
Ada_autocommit: Enables or disables automatic changes.
Ada_close: close the Adabas D link.
Ada_commit: change the Adabas D database.
Ada_connect: link to the Adabas D database.
Ada_exec: executes SQL commands.
Ada_fetchrow: returns a column.
Ada_fieldname: obtains the field name.
Ada_fieldtype: obtains the field data form.
Ada_freeresult: refers to the memory used to send data back.
Ada_numfields: obtains the number of fields.
Ada_numrows: gets the number of returned columns.
Ada_result: obtain the returned data.
Ada_resultall: returns HTML table data.
Ada_rollback: undo the current transaction.
AddSlashes: Adds a slash to the string.
Apache_lookup_uri: obtains information about all URIs.
Apache_note: obtain and set the request records of the Apache server.
Array: create a new array.
Array_walk: Enables user-defined functions to process every element in the array.
Arsort: sorts the array values from large to small.
Asin: returns the arc sine.
Asort: sorts the array values from small to large.
Aspell_check: check a single word.
Aspell_check-raw: check for a single word without changing or correcting it even if the spelling is wrong.
Aspell_new: load a new dictionary.
Aspell_suggest: checks a single word and provides suggestions for spelling.
Atan: Get the arc tangent value.
Atan2: calculate the arc tangent value of the second number.
Base64_decode: decodes the BASE64 encoded string.
Base64_encode: base64-encoded string.
Basename: returns a file string without a path.
Base_convert: convert the carry mode of numbers.
Bcadd: add two high-precision numbers.
Bccomp: compares two high-precision numbers.
Bcdiv: Division of two high-precision numbers.
Bcmod: obtain the remainder of a high-precision number.
Bcmul: multiply two high-precision numbers.
Bcpow: calculate the power of a high-precision number.
Bcscale: set the number of decimal places in all BC library in the program.
Bcsqrt: calculates the square root of a precise number.
Bcsub: subtract two high-precision numbers.
Bin2hex: binary to hexadecimal.
BinDec: binary to decimal.
Ceil: calculates the smallest integer greater than the specified number.
Chdir: change the directory.
Checkdate: verify that the date is correct.
Checkdnsrr: check the DNS records of the specified website.
Chgrp: change the group to which the archive belongs.
Chmod: change the attributes of an archive.
Chop: removes consecutive gaps.
Chown: changes the owner of an archive.
Chr: return the character of the ordinal value.
Chunk_split: splits a string into segments.
Clearstatcache: clears the file status cache.
Closedir: close the directory handle.
Closelog: Shut down system records.
Connection_aborted: Returns true if the link is interrupted.
Connection_status: Gets the connection status.
Connection_timeout: If the PHP program execution time is exceeded, true is returned.
Convert_cyr_string: convert the ancient Slavic string to another string.
Copy: copy an object.
Cos: returns the cosine.
Count: calculates the number of elements in a variable or array.
Crypt: encrypt the string using DES encoding.
Current: returns the current element in the array.
Date: format the server time.
Dbase_add_record: add data to the dBase table.
Dbase_close: close the dBase data table.
Dbase_create: Create a dBase data table.
Dbase_delete_record: delete the data in the dBase data table.
Dbase_get_record: obtain the data in the dBase data table.
Dbase_numfields: obtains the number of columns in The dBase data table.
Dbase_numrecords: gets the number of columns in The dBase data table.
Dbase_open: enables dBase tables.
Dbase_pack: Clear the dBase data table.
Dba_close: close the database.
Dba_delete: delete the specified data.
Dba_exists: Check whether the key exists.
Dba_fetch: retrieves the specified data.
Dba_firstkey: retrieves the first key value.
Dba_insert: add data.
Dba_nextkey: retrieves the next key value.
Dba_open: enable the database link.
Dba_optimize: optimizes the database.
Dba_popen: Enable and maintain the database connection.
Dba_replace: update or add data.
Dba_sync: synchronize databases.
Dblist: obtains DBM information.
Dbmclose: disable the DBM database.
Dbmdelete: delete specified data.
Dbmexists: Check whether the key exists.
Dbmfetch: retrieves the specified data.
Dbmfirstkey: retrieve the first key name.
Dbminsert: add materials.
Dbmnextkey: retrieves the next key value.
Dbmopen: enables the DBM Database link.
Dbmreplace: change or add data.
Debugger_off: disable the built-in PHP debugger.
Debugger_on: Use the built-in PHP debugger.
DecBin: decimal to binary.
DecHex: decimal to hexadecimal.
DecOct: decimal to octal.
Delete: useless project.
Die: output the message and interrupt the PHP program.
Dir: Directory class object.
Dirname: Get the directory name in the path.
Diskfreespace: obtain the available space of the Directory.
Dl: load the PHP expansion module.
Doubleval: converts a variable to a double floating point number type.
Each: returns the index and value of the next element in the array.
Easter_date: calculate the Easter date.
Easter_days: calculates the number of days between Easter and January 1, lunar March 21.
Echo: output string.
Empty: determines whether the variable has been set.
End: indicates the internal indicator of the array to the final element.
Ereg: string comparison analysis.
Eregi: string comparison analysis, which is case-insensitive.
Eregi_replace: analyzes and replaces strings, regardless of case.
Ereg_replace: analyzes and replaces string comparison.
Error_log: Sends an error message.
Error_reporting: sets the error message return level.
Escapeshellcmd: removes special characters from the string.
Eval: place the value in the string.
Exec: run an external program.
Exit: End the PHP program.
Exp: the power of natural logarithm e.
Explode: cut string.
Extract: imports the array to the symbol table.
Fclose: close an opened file.
FDF_close: close the FDF file.
FDF_create: create a new FDF file.
FDF_get_file: Gets the/F key value.
FDF_get_status: Gets the value of the/STATUS key.