1 /* Reads a string from stdin and converts it to uppercase or lowercase 2 * depending on an option readed from stdin */ 3 4 #include <stdio.h> 5 #include <stdlib.h> 6 #include <string.h> 7 #include <ctype.h> 8 9 #define MSG_STR_PROMPT "Introduzca una cadena:" 10 #define MSG_FMT_PROMPT "Convertir a: (0 - MAYUSCULAS / 1 - MINUSCULAS)" 11 #define MSG_FMT_ERR "Err: Formato incorrecto" 12 13 #define MAX_STR_LEN 100 14 15 typedef enum { 16 FMT_MAYUSCULAS, FMT_MINUSCULAS 17 } format_t; 18 19 20 int 21 main (void) 22 { 23 char buffer[MAX_STR_LEN]; 24 char str[MAX_STR_LEN]; 25 format_t format; 26 27 printf("%s%s", MSG_STR_PROMPT, "\n>> "); 28 fgets(buffer, MAX_STR_LEN, stdin); 29 strcpy(str, buffer); 30 31 printf("%s%s", MSG_FMT_PROMPT, "\n>> "); 32 format = (getchar () - '0'); 33 if((format < 0) || (format > 1)) { 34 fprintf(stderr, "%s\n", MSG_FMT_ERR); 35 return 1; 36 } 37 38 int i, aux; 39 switch(format) 40 { 41 case FMT_MAYUSCULAS: 42 for(i = 0; (aux = str[i]) != '\n'; i++) 43 if(islower(aux)) 44 str[i] = toupper(aux); 45 46 break; 47 case FMT_MINUSCULAS: 48 for(i = 0; (aux = str[i]) != '\n'; i++) 49 if(isupper(aux)) 50 str[i] = tolower(aux); 51 52 break; 53 } 54 55 printf("%s", str); 56 return 0; 57 }
