HarvardCS50/pset3/recover/recover.c

65 lines
1.4 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <cs50.h>
int main(int argc, char *argv[])
{
// check if valid argument counter
if (argc != 2)
{
printf("Usage: ./recover file.jpg\n");
return(1);
}
// initialize input as variable
FILE *inptr = fopen(argv[1], "r");
// open up the file and check if valid file
if ( inptr == NULL )
{
printf("Could not open file\n");
return(2);
}
//global variables
unsigned char buffer[512];
FILE *img = NULL;
int counter = 0;
char filename[8];
//Setup loop
while (true)
{
int read = fread(&buffer, 512, 1, inptr);
// break if at EOF
if (read != 1)
{
break;
}
// check if at start of file
if (buffer[0] == 0xff && buffer[1] == 0xd8 && buffer[2] == 0xff && (buffer[3] & 0xf0) == 0xe0)
{
// If not at first run, close last file
if (img != NULL)
{
fclose(img);
}
// open up new file since we are at start
sprintf(filename, "%03i.jpg", counter);
img = fopen(filename, "w");
counter ++;
}
// only write to the file if we are not in the first run!!!!
if (img != NULL)
{
fwrite(&buffer, 512, 1, img);
}
}
fclose(img);
fclose(inptr);
}