28 lines
597 B
C
28 lines
597 B
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <fcntl.h>
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int main(int argc, char *argv[]){
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if (argc != 4){
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fprintf(stderr, "%c <file_name> <32-bit in Hex> <Offset in Hex>", argv[0]);
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exit(1);
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}
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off_t offset;
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ssize_t nb_write;
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int nb, n;
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int fdin;
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fdin = open(argv[1],O_WRONLY);
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if (fdin == -1){
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perror("File can't be opened");
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exit(2);
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}
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offset = (off_t) strtol (argv[3], NULL, 16);
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nb = (int) strtol(argv[2], NULL, 16);
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n = lseek(fdin, offset * sizeof(int), SEEK_SET);
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nb_write=write(fdin, &nb, sizeof(int));
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printf("%x", nb);
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return EXIT_SUCCESS;
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}
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