Dynamic allocation for text input

[Hengist]

I'm trying to accept arbitrary length strings from stdin. I know that you can't do that automatically in C, so I ask the user to input the size of each string, allocate the memory for it, and then read the string.

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

int main(void)
{
	char *source_string = NULL;
	char *search_string = NULL;
	int source_length = 0, search_length = 0;
	
	puts("How long is your source string?");
	scanf("%d", &source_length);
	source_string = (char *)malloc(source_length + 1);
	puts("Please enter your source string.");
	scanf("%s", &source_string);
	
	puts("How long is your search string?");
	scanf("%d", &search_length);
	search_string = (char *)malloc(search_length + 1);
	puts("Please enter your search string.");
	scanf("%s", &search_string);
	
	printf("Now searching string \"%s\" for characters \"%s\".\n", &source_string, &search_string);

	puts("Cleaning up memory...");
	free(source_string);
	free(search_string);
	
	return EXIT_SUCCESS;
}

Unfortunately, it doesn't work properly. I've included a sample run below.

How long is your source string?
3
Please enter your source string.
123
How long is your search string?
6
Please enter your search string.
123456
Now searching string "56" for characters "123456".
Segmentation fault

Thanks in advance for any help!

[gpraghuram]

Check this.
I have corrected few issues in the code
[code=c]
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
char *source_string = NULL;
char *search_string = NULL;
int source_length = 0, search_length = 0;

puts("How long is your source string?");
scanf("%d", &source_length) ;
source_string = (char *)malloc(source _length + 1);
puts("Please enter your source string.");
scanf("%s", source_string);

puts("How long is your search string?");
scanf("%d", &search_length) ;
search_string = (char *)malloc(search _length + 1);
puts("Please enter your search string.");
scanf("%s", search_string);

//printf("Now searching string \"%s\" for characters \"%s\".\n", &source_stri ng, &search_string) ;
printf("Now searching string \"%s\" for characters \"%s\".\n", source_string, search_string);

puts("Cleaning up memory...");
free(source_str ing);
free(search_str ing);

return EXIT_SUCCESS;
}
[/code]

Raghuram

[Hengist]

I can't believe I missed that. <shakes head>
It works perfectly now. Thank you for your help!