39 lines
639 B
C
39 lines
639 B
C
#include<stdio.h>
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#include<fcntl.h>
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#include<unistd.h>
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#include<stdlib.h>
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#include <string.h>
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#define szbuf 256
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int main(int argc, char const *argv[])
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{
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char buf[szbuf];
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int fd,x;
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off-t l;
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unsigned int x;
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long int i, offset;
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if(argc<4)
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{
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fprintf(stderr, "Usage: %s ./get_numb <file_name> <offset>",argv[1]);
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exit(1);
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}
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fd = open(argv[1],O_RDONLY);
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if(fd == -1)
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{
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perror("Opening file fails");
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exit(2);
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}
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x = (unsigned int) strtol(argv[2],NULL,16);
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i = (unsigned int) strtol(argv[3],NULL,16);
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offset = i x sizeof(int);
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l = lseek(fd,0,SEEK_SET);
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if(l == -1)
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{
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close(fd);
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exit(3);
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}
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close(a);
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exit(0);
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} |