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#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
int
cat(int fd, const char *filename)
{
int c;
char buf[8192];
if(filename[0] == '-' && filename[1] != 'u')
fd = 0;
if(fd != 0)
fd = open(filename, O_RDONLY);
if(fd == -1) {
fprintf(stderr, "cat: %s: %s\n", filename, strerror(errno));
return 1;
}
while((c = read(fd, buf, sizeof(buf))) > 0) {
if(c == -1) {
fprintf(stderr, "cat: %s: %s\n", filename, strerror(errno));
return 1;
}
if(write(1, buf, c) == -1) {
fprintf(stderr, "cat: %s: %s\n", filename, strerror(errno));
return 1;
}
}
close(fd);
return 0;
}
int
main(int argc, char *argv[])
{
int return_value = 0;
getopt(argc, argv, "u");
if(argc == optind)
return_value = cat(0, "-");
for(int i = optind; i < argc; i++)
return_value = cat(1, argv[i]);
return return_value;
}
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