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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NUL '\000'
#define BEL '\007'
#define LINE_LEN 132
void give_up(char *msg)
{
putchar(BEL);
puts(msg);
exit(-1);
}
int main(int argc, char *argv[])
{
FILE *infile;
char line[LINE_LEN + 2]; /* Allow for '\n' & NUL */
int i, N = 0;
if (2 > argc)
give_up("Usage: HEAD file [number_of_lines]");
if (NULL == (infile = fopen(argv[1], "r")))
give_up("Unable to open input file");
if (2 < argc)
N = atoi(argv[2]);
if (!N) N = 4;
for (i = 0; i < N; ++i)
{
if (NULL == fgets(line, LINE_LEN + 1, infile))
break;
line[LINE_LEN + 1] = NUL; /* Allow too-long lines */
fputs(line, stdout);
if (!strrchr(line, '\n'))
i -= 1; /* More to read */
}
fclose(infile);
return EXIT_SUCCESS;
}
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