C Programming

BUILT IN FUNCTIONS FOR STRING HANDLING

string.h
You may want to look at the section on arrays first!. The following macros are built into the file string.h


	strcat          Appends a string
	strchr          Finds first occurrence of a given character
	strcmp          Compares two strings
	strcmpi         Compares two strings, non-case sensitive
	strcpy          Copies one string to another
	strlen          Finds length of a string
	strlwr          Converts a string to lowercase
	strncat         Appends n characters of string
	strncmp 	Compares n characters of two strings
	strncpy         Copies n characters of one string to another
	strnset         Sets n characters of string to a given character
	strrchr         Finds last occurrence of given character in string
	strrev          Reverses string
	strset          Sets all characters of string to a given character
	strspn          Finds first substring from given character set in string
	strupr          Converts string to uppercase

To convert a string to uppercase

	#include <stdio.h>
	#include <string.h>

	main()
	{
		char name[80];	/* declare an array of characters 0-79 */

		printf("Enter in a name in lowercase\n");
		scanf( "%s", name );
		strupr( name );
		printf("The name is uppercase is %s", name );
	}


	Sample Program Output
	Enter in a name in lowercase
	samuel
	The name in uppercase is SAMUEL

BUILT IN FUNCTIONS FOR CHARACTER HANDLING
The following character handling functions are defined in ctype.h


	isalnum         Tests for alphanumeric character
	isalpha         Tests for alphabetic character
	isascii         Tests for ASCII character
	iscntrl         Tests for control character
	isdigit         Tests for 0 to 9
	isgraph         Tests for printable character
	islower         Tests for lowercase
	isprint         Tests for printable character
	ispunct         Tests for punctuation character
	isspace         Tests for space character
	isupper         Tests for uppercase character
	isxdigit        Tests for hexadecimal
	toascii         Converts character to ascii code
	tolower         Converts character to lowercase
	toupper         Converts character to uppercase

To convert a string array to uppercase a character at a time using toupper()


	#include <stdio.h>
	#include <ctype.h>
	main()
	{
		char name[80];
		int loop;

		printf("Enter in a name in lowercase\n");
		scanf( "%s", name );
		for( loop = 0; name[loop] != 0; loop++ )
			name[loop] = toupper( name[loop] );

		printf("The name is uppercase is %s", name );
	}


	Sample Program Output
	Enter in a name in lowercase
	samuel
	The name in uppercase is SAMUEL