(ANSI) C Language Functions Reference

C Language Reference Tables

• Unary and Binary Operator Table

C Library Functions

• abort() - Abort the current process
• abs() - Absolute value
• acos() - the arc cosine of x in radians
• asctime() - Convert tm structure to string
• asin() - the arc sine of x in radians
• atan() - the arc tangent of x in radians
• atan2() - the arc tangent in radians of y/x
• atexit() - Set function that must be executed on exit
• atof() - Convert a string to a double
• atoi() - Convert a string to an integer
• atol() - Convert a string to a long integer
• bsearch() - Binary search in array
• calloc() - Allocate space for an array in memory
• ceil() - the smallest integer value greater than or equal to x
• clock() - Clock ticks elapsed since the start of the program
• cos() - the cosine of a radian angle
• cosh() - the hyperbolic cosine
• ctime() - Convert time_t value to string
• difftime() - Difference between two times
• div() - Integral division
• exit() - Terminate calling process
• exp() - exponential value
• fabs() - the absolute value of x
• floor() - the largest integer value less than or equal to x
• fmod() - the remainder of x divided by y
• free() - De-allocate space in memory
• frexp() - significand and exponent
• getenv() - Get the environment string
• gmtime() - Convert calendar time to UTC
• isalnum() - Alphanumeric test
• isalpha() - Alphabetic test
• iscntrl() - Control character test
• isdigit() - Decimal digit test
• isgraph() - Printing character test (Space is not included)
• islower() - Lower case letter test
• isprint() - Printing character test (Space included)
• ispunct() - Printing character (except space,digit,letter)
• isspace() - Space, tab, vtab, formfeed, newline, cr test
• isupper() - Upper case letter test
• isxdigit() - Hexidecimal digit test
• labs() - Absolute value
• ldexp() - return x multiplied by 2 raised to the power of exponent
• ldiv() - Integral division
• localtime() - Convert calendar time to local time
• log() - the natural logarithm (base-e logarithm)
• log10() - the common logarithm (base-10 logarithm)
• malloc() - Allocate a memory block
• mblen() - Get length of a multi-byte character
• mbtowc() - Convert a multi-byte character to wide character
• memchr() - Pointer to the first occurence c in the first n bytes of a memory area
• memcmp() - Compare n characters of target with source
• memcpy() - Copy n characters from source to target
• memmove() - Copy n characters from source to target (even with overlap)
• memset() - Copies x into a buffer y and does this n times.
• mktime() - Convert the tm structure to time_t
• modf() - break into fractional and integral
• pow() - x raised to the power of y
• qsort() - Sort elements of array
• rand() - Generate random number
• realloc() - Reallocate a memory block
• sin() - the sine of a radian angle
• sinh() - the hyperbolic sine
• sqrt() - the square root
• srand() - Initialize random number generator
• strcat() - Concatenates one string onto the end of another string
• strchr() - Pointer to first occurrence of x in a string
• strcmp() - Compares two strings
• strcpy() - Copy of a string
• strftime() - Format date and time
• strlen() - Length of a string
• strncat() - Concatenates up to n characters
• strncmp() - Compares up to n characters
• strncpy() - Copy of a string up to n characters
• strrchr() - Pointer to last occurrence of x in a string
• strstr() - Pointer to first occurrence of x in a string
• strtod() - Convert a string to a double
• strtol() - Convert a string to a long integer
• strtoul() - Convert a string to an unsigned long integer
• system() - Execute system commands
• tan() - the tangent of a radian angle
• tanh() - the hyperbolic tangent
• time() - Current calendar time
• tolower() - Convert to lower case
• toupper() - Convert to upper case