Standard String Functions

Source Code

<source lang="c">

1. include <dev/board.h>
2. include <io.h>
3. include <stdio.h>
4. include <string.h>
5. include <stdlib.h>

int main(void) {

   unsigned long baud = 115200;
   char buffer[50];
   char buffer2[50];
   int l;
   char *s;

   NutRegisterDevice(&DEV_DEBUG, 0, 0);

   freopen(DEV_DEBUG_NAME, "w", stdout);
   _ioctl(_fileno(stdout), UART_SETSPEED, &baud);

   /* Copy "Hello" to the string. */
   strcpy(buffer, "Hello");
   
   /* Append " World" to buffer. */
   strcat(buffer, " World");
   printf("Text: %s\n", buffer);

   /* Calculate the length of the string. */
   l = strlen(buffer);
   printf("Text is %d Characters long\n", l);

   /* Compare two strings. */
   if (strcmp(buffer, "Hello World") == 0) {
       printf("Both strings are equal\n");
   }

   /* Look for the character 'l'. */
   s = strchr(buffer, 'l');
   if (s != NULL) {
       printf("'l' is at character %ld\n", s - buffer + 1);
   }

   /* Look for the string "World". */
   s = strstr(buffer, "World");
   if (s != NULL) {
       printf("\"World\" is at character %ld\n", s - buffer + 1);
   }

   /* Copy the first 5 characters to buffer2. */
   strncpy(buffer2, buffer, 5);
   buffer2[5] = '\0';
   printf("buffer2: %s\n", buffer2);

   /* Append 7 characters of " DeviceDevice" to buffer2. */
   strncat(buffer2, " DeviceDevice", 7);
   printf("buffer2: %s\n", buffer2);

   /* Compare the first 6 characters of buffer and buffer2. */
   if (strncmp(buffer, buffer2, 6) == 0) {
       printf("The first 6 characters are equal\n");
   }

   /* Look for the last character 'v'. */
   s = strrchr(buffer2, 'v');
   if (s != NULL) {
       printf("'v' is at character %ld\n", s - buffer2 + 1);
   }

   /* Create a copy of buffer2 and destroy it. */
   s = strdup(buffer2);
   printf("s: %s\n", s);
   free(s);
   s = NULL;

   /* Compare two strings case-insensitive. */
   if (strcasecmp(buffer2, "hello device") == 0) {
       printf("strcasecmp: equal\n");
   }

   /* Compare 6 character of two strings case-insensitive. */
   if (strncasecmp(buffer2, "hello world", 6) == 0) {
       printf("strncasecmp: equal\n");
   }
   /* Split buffer at all spaces. */
   s = strtok(buffer, " ");
   while (s != NULL) {
       printf("strtok: %s\n", s);
       s = strtok(NULL, " ");
   }

   /* Convert a string into lower case. */
   strlwr(buffer2);
   printf("buffer2: %s\n", buffer2);

   /* Convert a string into upper case. */
   strupr(buffer2);
   printf("buffer2: %s\n", buffer2);

   /* Look for the characters 'L' and 'V'. */
   s = strpbrk(buffer2, "LV");
   while (s != NULL) {
       printf("'%c' is at character %ld\n", *s, s - buffer2 + 1);
       s = strpbrk(s + 1, "LV");
   }

   /* Look for the character 'O' in buffer2. */
   l = strcspn(buffer2, "O");
   printf("'O' is at character %d\n", l + 1);

   /* Calculate how many characters at the beginning are E, H or L. */
   l = strspn(buffer2, "EHL");
   printf("%d characters at the beginneing are E, H or L\n", l);

   for (;;);

   return 0;

} </source>

Output

Text: Hello World                                                               
Text is 11 Characters long                                                      
Both strings are equal                                                          
'l' is at character 3                                                           
"World" is at character 7                                                       
buffer2: Hello                                                                  
buffer2: Hello Device                                                           
The first 6 characters are equal                                                
'v' is at character 9                                                           
s: Hello Device                                                                 
strcasecmp: equal                                                               
strncasecmp: equal                                                              
strtok: Hello                                                                   
strtok: World                                                                   
buffer2: hello device                                                           
buffer2: HELLO DEVICE                                                           
'L' is at character 3                                                           
'L' is at character 4                                                           
'V' is at character 9                                                           
'O' is at character 5                                                           
4 characters at the beginneing are E, H or L