Lesson 11: Standard Library Functions.
Following is the list of selected standard library functions. The functions have been classified into broad categories.
Arithematic Functions:
1) abs() - Retyrns the absolute value of an integer.
2) cos() - Calculate cosine.
3) exp() - Raises the exponential e to the xth power.
4) floor() - Finds largest integer less than or equal to argument.
5) log() - Calculates natural logarithm.
6) log10 - Calculates base 10 logarithm.
7) pow() - Calculates a value of raised power.
8) sin() - Calculates sine.
9) sqrt() - Calculates square root.
10) tan() - Calculates tangent.
Data Conversion Functions:
1) atof() - Converts string to float.
2) atoi() - Converts string to integer.
3) atol()- Converts string to long.
4) ecvt() - Converts double to string.
5) itoa() - Converts int to string.
6) ltoa() - Converts long to string.
7) strtod() - Converts string to double.
8) strtll() - Converts string to long integer.
9) strtoul - Converts string to unsigned long integer.
10) ultoa() - Converts unsigned long to string.
Character Classification Functions:
1) isalnum() - Tests for alphanumeric character.
2) isalpha() - Test for alphabetic character.
3) isdigit() - Test for decimal digit.
4) islower() - Test for lower case.
5) isprint() - Test for printable character.
6) ispunct() - Test for punctuation mark.
7) isspace() - Test for a white space character.
8) isupper() - Test for an uppercase character.
9) tolower() - Test character and converts to lower case if uppercase.
10) toupper() - Text character and converts to uppercase if lowercase.
The above functions return a non-zero value if they are true otherwise returns zero if they are false.
String Manipulation Functions:
1) strcat() - Appends one string to another.
2) strchr() - Finds first occurence of a given character in a string.
3) strcmp() - Compares two strings.
4) strcmpi() - Compares two strings without regard to case.
5) strcpy() - Copies one string to another.
6) strlen() - Finds length of a string.
7) strlwr() - Converts a string to lower case.
8) strupr() - Converts a string to upper case.
9) strstr() - Finds first occurence of a given string in another string.
10) strrev() - Reverse a string.
File Handling Functions:
1) remove() - Deletes files.
2) rename() - Renames file.
3) unlink() - Deletes files.
Memory Allocation Functions:
1) calloc() - Allocates a block of memory.
2) free() - Frees a block allocated with malloc.
3) malloc() - Allovcates a block of memory.
Process Control Functions:
1) abort() - Abort a process.
2) exit() - Terminates the process.
3) system() - Executes an MS-DOS command.
Time Related Functions:
1) clock() - Returns the elapsed CPU time for a process.
2) difftime() - Computed the difference between two times.
3) ftime() - Gets current system time as structure.
4) strdate() - Returns the current system date as a string.
5) strtime() - Returns the current system timje as a string.
6) time() - Gets current system time as a long integer.
7) setdate() - Sets DOS date.
8) getdate() - Get system date.