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

// strcpy example
int s1(void)
{
    char ha[30];
    strcpy(ha, "Now is the the time");
    printf("%s\n%d\n", ha, strlen(ha));
}

// strcpy and strcar
int s2(void)
{
    char ha[50];
    strcpy(ha, "Now is the time");
    strcat(ha, " for all good men");
    printf("%s\n", ha);
}

/*******
*** stack smashing detected ***: <unknown> terminated
Aborted (core dumped)
 *******/
int s3(void)
{
    char ha[15];
    strcpy(ha, "Now is the");
    strcat(ha, " time for all good men to come");
    printf("%s\n", ha);
}

//strlen example
int s4(char str[])
{
    printf("Length: %d\n", strlen(str));
}


// my implementation of strlen, with a bounded string length
// will return -1 if get to bound before null terminator
int s5(const char * str, int maxlen)
{
    int len=0;
    for (len=0; len<2048; len++)
    {
	if (*(str++)=='\0')
	{
	    printf("Length: %d\n", len);
	    return len;
	    break;
	}
    }
    return -1;
}

// no null terminator
int s6()
{
    char aa[2048];
    for (int i=0;i<26;i++)
    {
	aa[i]='A'+i;
    }
    printf("length: %d\n", strlen(aa));
    for (int i=21; i<30; i++)
    {
	printf("%2d  |%c| %d\n", i, aa[i], aa[i]);
    }
}

// My strcpy.  Assumes that target has the space
int s7(char * target, const char * source)
{
    for (int i=0; source[i]!=0; i++)
    {
	target[i]=source[i];
    }
}

// my strcpy with pointers
char * s8(char * target, const char * source)
{
    char * tar = target;
    while (*tar++ =*source++);
    return target;
}

// compare to s3
int s9()
{
    char tgt[100];
    sprintf(tgt, "%s %s", "now is the time", "for all good men");
    printf("%s\n", tgt);
    return 0;
}
    
//Usage: a.out NUM
// where NUM indicates the sample you want to run
// NUM shouuld be in 1-8 inclusive
int main(int argc, char * argv[])
{
    switch (argv[1][0])
    {
    case '1':
	s1();
	break;
    case '2':
	s2();
	break;
    case '3':
	s3();
	break;
    case '4':
	s4("Now is the time");
	break;
    case '5':
	s5("for all good men to come to the aid");
	break;
    case '6':
	s6();
	break;
    case '7':
    {
	char tar[2048];
	s7(tar, "Now is the time for all good men to come to the aid of their party");
	printf("Copied: %s\n", tar);
	}
	break;
    case '8':
    {
	char tar[2048];
	s8(tar, "Now is the time for all good men to come to the aid of their party");
	printf("Copied: %s\n", tar);
	}
	break;
    default:
	printf("SWITCH:What to do with %s\n", argv[1][0]);
	break;
    }
}