reverse.c

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

int slen(const char * string){
    int i=0;
    while(string[i]!='\0'){
        i++;
    }
    return i+1;
}
char * scpy(const char * string){
    char * p;
    int len = slen(string);
    p = (char *)malloc(len);
    int i;
    for(i=0; i<len; i++){
        p[i] = string[i];
    }
    return p;
}
int main(int argc, char *argv[])
{
    char * p;
    p = scpy(argv[1]);
    int i,len;
    len = slen(p);
    int tmp=len;
    for(i=len;i>=0;i--){
        if(p[i]==' ' || i == 0){
            int j;
            for(j=(i==0)?i:i+1;j<tmp;j++){
                printf("%c",p[j]);
            }
            printf(" ");
            tmp=i;
        }
    }
    printf("\n");
    free(p);
    return 0;
}