| 1 | #include <stdio.h> |
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| 2 | #include <fcntl.h> |
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| 3 | |
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| 4 | #define BLOCK_SIZE 0x1000 |
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| 5 | |
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| 6 | unsigned char data[BLOCK_SIZE]; |
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| 7 | unsigned char out_data[BLOCK_SIZE]; |
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| 8 | |
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| 9 | #define SWAP_INT(x) ((((unsigned int)x & 0xFF) << 24) |(((unsigned int)x & 0xFF00) << 8) |(((unsigned int)x & 0xFF0000) >> 8) | (((unsigned int)x & 0xFF000000) >> 24)) |
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| 10 | |
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| 11 | int main(int argc, char * argv[]) |
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| 12 | { |
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| 13 | FILE * input; |
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| 14 | FILE * output; |
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| 15 | size_t read_count; |
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| 16 | size_t write_count; |
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| 17 | unsigned long * walker; |
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| 18 | unsigned long * out_walker; |
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| 19 | /* uncomment this if compiling on cygwin */ |
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| 20 | #if 0 |
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| 21 | if(-1 == setmode(fileno(stdin), O_BINARY)){ |
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| 22 | perror("Cannot set stdin to binary mode"); |
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| 23 | return -1; |
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| 24 | } |
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| 25 | if(-1 == setmode(fileno(stdout), O_BINARY)){ |
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| 26 | perror("Cannot set stdout to binary mode"); |
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| 27 | return -1; |
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| 28 | } |
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| 29 | #endif |
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| 30 | do{ |
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| 31 | read_count = fread(data, 1, BLOCK_SIZE, stdin); |
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| 32 | if((0 != (read_count & 3))&&(0 != read_count)){ |
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| 33 | fprintf(stderr, "Input size must be divisible by 4!\n"); |
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| 34 | return -1; |
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| 35 | } |
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| 36 | if(read_count != 0){ |
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| 37 | walker = (unsigned long*)data; |
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| 38 | out_walker = (unsigned long*)out_data; |
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| 39 | while(walker != (unsigned long*)(&data[BLOCK_SIZE])) { |
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| 40 | *out_walker = SWAP_INT(*walker); |
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| 41 | out_walker++; walker++; |
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| 42 | } |
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| 43 | |
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| 44 | write_count = fwrite(out_data, 1, read_count, stdout); |
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| 45 | if(read_count != write_count){ |
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| 46 | perror("Unable to write data"); |
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| 47 | return -1; |
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| 48 | } |
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| 49 | } |
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| 50 | }while(BLOCK_SIZE == read_count); |
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| 51 | |
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| 52 | return 0; |
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| 53 | } |
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