C-Code

/*******************************
 * loeffel.c    Loeffelsprache
 *******************************/
#include <ctype.h>
#include <stdio.h>
 
void loeffel(const char *text) {
    const char *p = text;
    int c, l;
    
    while ((c = *p)) {
        l = tolower(c);
		if (l=='a' || l=='e' || l=='i' || l=='o' || l=='u')
			printf("%c%s%c", c, "lew", l);
		else			
			putchar(c);
		p++;		
	}
	putchar('\n');
}

int main(int argc, char **argv) {
	if (argc > 1) 
		loeffel(argv[1]);
	return 0;
}

C-Code

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    int groesse, stelle_loeffel,i;
    
    groesse = 30;
    stelle_loeffel = 0;
    i=0;
    char text[groesse];
    char loeffel[groesse*4];
    
    printf("Welcher Satz soll in Löffelsprache umgewandelt werden?\n");
    fgets(text,groesse,stdin);
    
    while (text[i]!='\0')
    {
        if (text[i]=='i' || text[i]=='I' || text[i]=='a' || text[i]=='A' || text[i]=='e' || text[i]=='E' || text[i]=='o' || text[i]=='O' || text[i]=='u' || text[i]=='U') {
            loeffel[stelle_loeffel] = text[i];
            loeffel[stelle_loeffel+1] = 'l';
            loeffel[stelle_loeffel+2] = 'e';
            loeffel[stelle_loeffel+3] = 'w';
            loeffel[stelle_loeffel+4] = text[i];
            stelle_loeffel = stelle_loeffel + 5;
        }
        else {
            loeffel[stelle_loeffel]= text[i];
            stelle_loeffel++;
        }
        i++;
    }
    
    for (i=0;i<=stelle_loeffel;i++)
    {
        printf("%c", loeffel[i]);
    }
    printf("\n");
    return EXIT_SUCCESS;
}