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#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/fcntl.h>
int verbose=0;
void usage(char *prog) {
fprintf(stderr, "usage: %s [-v] <file>\n", prog);
exit(-1);
}
char *map(char *file, size_t *len) {
struct stat s;
char *buf;
int fd;
if ( (fd = open(file, O_RDONLY)) == -1) {
fprintf(stderr,"can't open %s: %s\n", file, strerror(errno));
exit(-1);
}
if (fstat(fd, &s) == -1) {
close(fd);
fprintf(stderr,"can't stat %s: %s\n", file, strerror(errno));
exit(-1);
}
*len = s.st_size;
buf = mmap(0, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (buf == MAP_FAILED) {
close(fd);
fprintf(stderr, "failed to mmap %s: %s\n", file, strerror(errno));
exit(-1);
}
/* don't: close(fd); */
return buf;
}
int main(int argc, char * argv[]) {
int opt;
char *file, *buf;
size_t len;;
while ( (opt = getopt(argc, argv, "v+")) != -1) {
switch (opt) {
case 'v':
verbose++;
break;
default:
usage(argv[0]);
break;
}
}
if (optind < argc) file=argv[optind++];
else usage(argv[0]);
buf = map(file, &len);
printf("mmap'd %s: %u bytes\n", file, (unsigned)len);
}
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