Utility Functions and C Language Reference > C Language Reference > Alphabetical Listing of C Functions

Alphabetical Listing of C Functions

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Function Name
Description
Gets the absolute value of an integer.
Converts time from a structure to a string.
Converts a string to a floating point value.
Converts a string to an integer value.
Converts a string to a long integer value.
Allocates an array and initializes all elements to zero.
Changes the current directory to the given path. (Windows only)
Switches to another drive.
Computes the cosine of an angle in radians.
Converts the calendar time to local time.
Closes a file.
Checks if the end of file has occurred on a stream.
Checks if any error has occurred during file I/0.
Gets a character from a stream.
Reads a string from a file.
ftell Returns the current file position of the given stream.
Gets the largest integral value that is less than x.
Opens a file for buffered I/0.
Writes formatted output to a file.
Writes a character to a stream.
Reads unformatted data from a stream into a buffer.
Frees a block of memory.
Reads formatted input from a stream.
Sets the current position in a file to a new location.
Write unformatted data from a buffer to a stream.
Returns the name of the current working directory.
Returns the name of the current drive.
Gets the definition of an environment variable.
Converts the calendar time into Coordinated Universal Time (UTC).
Checks if a string is a letter.
Checks if a string is a decimal digit.
Converts the calendar time into local time.
Allocates a block of memory.
Searches for a character in a buffer.
Compares two buffers.
Copies n characters from one buffer into another.
Moves a number of bytes from one buffer to another.
Sets n bytes of a buffer to a given character.
Creates a directory using the given path name.
Inserts a new definition into an environment table.
Gets a random integer between 0 and 32767.
Reallocates (adjusts the size of) a block of memory.
Deletes the specified file.
Rewinds a file.
Deletes the specified directory.
Computes the sine of an angle in radians.
Writes formatted output to a string.
Computes the square root of x.
Reads formatted input from a string.
Concatenates two strings.
Returns the pointer to the first occurrence of a character in a string.
Compares two strings to determine the alphabetic order.
Copies one string to another.
Duplicates a string.
Converts time to a string, and writes the string into a memory area.
Performs a case-insensitive comparison of two strings.
Returns the length of a string.
Concatenates n characters from one string to another.
Compares the first n characters of two strings.
Copies the first n characters of one string to another.
Performs a case-insensitive comparison of n strings.
Finds the last occurrence of a character in a string.
Returns the length of the leading characters in a string that are contained in a specified string.
Returns the first occurrence of one string in another.
Returns a token from a string delimited by specified characters.
Converts a string to a long integer using a given radix.
Executes an operating system command.
Returns the current calendar time.
Converts a string to lowercase.
Converts a string to uppercase.