Abs: Get the absolute value.
Acos: Get the arc cosine value.
ada_afetch: Get the returned column from the database.
ada_autocommit: Switch the automatic change function.
ada_close: Close the Adabas D link.
ada_commit: Modify the Adabas D database.
ada_connect: Connect to the Adabas D database.
ada_exec: Execute SQL instructions.
ada_fetchrow: Get a column returned.
ada_fieldname: Get the field name.
ada_fieldtype: Get the field data form.
ada_freeresult: Release the memory of the returned data.
ada_numfields: Get the number of fields.
ada_numrows: Get the number of returned columns.
ada_result: Get the returned data.
ada_resultall: Returns HTML table data.
ada_rollback: Undo the current transaction.
AddSlashes: Add slashes to the string.
apache_lookup_uri: Get all URI related information.
apache_note: Get and set the Apache server's request record.
array: Create a new array.
array_walk: Allows user-defined functions to process each element in the array.
arsort: Sort the array values from large to small.
Asin: Get the arcsine value.
asort: Sort the array values from small to large.
aspell_check: Check a word.
aspell_check-raw: Checks a word and does not change or correct it even if it is misspelled.
aspell_new: Load a new dictionary.
aspell_suggest: Check a word and provide spelling suggestions.
Atan: Get the arctangent value.
Atan2: Calculates the arctangent of a two number.
base64_decode: Decode BASE64 encoded string.
base64_encode: Encode the string in BASE64.
basename: Returns the file string without path.
base_convert: Convert the carry method of the number.
bcadd: Add two high-precision numbers.
bccomp: Compares two high-precision numbers.
bcdiv: Divide two high-precision numbers.
bcmod: Get the remainder of a high-precision number.
bcmul: Multiply two high-precision numbers.
bcpow: Find the power of a high-precision number.
bcscale: Sets the default number of decimal points for all BC libraries in the program.
bcsqrt: Find the square root of a high-precision number.
bcsub: Subtract two high-precision numbers.
bin2hex: Convert binary to hexadecimal.
BinDec: Convert binary to decimal.
Ceil: Calculates the smallest integer greater than the specified number.
chdir: change directory.
checkdate: Verify the correctness of the date.
checkdnsrr: Check the DNS records of the specified URL.
chgrp: Change the group to which a file belongs.
chmod: Change file attributes.
Chop: Remove consecutive blanks.
chown: Change the owner of the file.
Chr: Returns the ordinal value of characters.
chunk_split: Divide the string into small segments.
clearstatcache: Clear the file status cache.
closedir: close the directory handle.
closelog: Close system logging.
connection_aborted: Returns true if the connection is interrupted.
connection_status: Get the connection status.
connection_timeout: Returns true if the PHP program execution time is exceeded.
convert_cyr_string: Convert Cyrillic strings into other strings.
copy: Copy the file.
Cos: cosine calculation.
count: Counts 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's time.
dbase_add_record: Add data to the dBase data table.
dbase_close: Close the dBase table.
dbase_create: Create dBase data table.
dbase_delete_record: Delete data from the dBase data table.
dbase_get_record: Get the data of dBase table.
dbase_numfields: Get the number of fields in the dBase data table.
dbase_numrecords: Get the number of columns in the dBase data table.
dbase_open: Open the dBase data table.
dbase_pack: Clean up the dBase data table.
dba_close: Close the database.
dba_delete: Delete specified data.
dba_exists: Check whether the key exists.
dba_fetch: Retrieve specified data.
dba_firstkey: Retrieve the first key value.
dba_insert: Add data.
dba_nextkey: Get the next key value.
dba_open: Open the database link.
dba_optimize: Optimize the database.
dba_popen: Open and maintain the database connection.
dba_replace: change or add data.
dba_sync: Database synchronization.
dblist: Get DBM information.
dbmclose: Close the DBM database.
dbmdelete: Delete specified data.
dbmexists: Check if the key exists.
dbmfetch: Retrieve specified data.
dbmfirstkey: retrieve the first key name.
dbminsert: Add data.
dbmnextkey: Get the next key value.
dbmopen: Open a DBM database link.
dbmreplace: change or add data.
debugger_off: Turn off the built-in PHP debugger.
debugger_on: Use the built-in PHP debugger.
DecBin: Convert decimal to binary.
DecHex: Convert decimal to hexadecimal.
DecOct: Convert decimal to octal.
delete: useless items.
die: Output a message and interrupt the PHP program.
dir: Directory category object.
dirname: Get the directory name in the path.
diskfreespace: Get the remaining free space where the directory is located.
dl: Load PHP extension module.
doubleval: Convert the variable into a double floating-point number type.
each: Returns the index and value of the next element in the array.
easter_date: Calculate Easter date.
easter_days: Calculate the number of days between Easter and March 21st.
echo: output string.
empty: Determines whether the variable has been set.
end: Points the internal pointer of the array to the last element.
ereg: String comparison analysis.
eregi: String comparison analysis, regardless of case.
eregi_replace: String comparison analysis and replacement, regardless of case.
ereg_replace: String comparison analysis and replacement.
error_log: Send an error message.
error_reporting: Set the level of error message reporting.
escapeshellcmd: Remove special symbols from strings.
eval: Substitute value into string.
exec: Execute external program.
exit: End the PHP program.
Exp: The natural logarithm e raised to the power.
explode: split the string.
extract: Import array into symbol table.
fclose: Close an open file.
FDF_close: Close the FDF file.
FDF_create: Create a new FDF file.
FDF_get_file: Get the value of /F key.
FDF_get_status: Get the value of the /STATUS key.