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#include "csapp.h"
static noreturn void usage(int argc, char *argv[]) {
fprintf(stderr, "Usage: %s [-t times] [-l length] -s "
"[write|fwrite|fwrite-line|fwrite-full|writev]\n", argv[0]);
exit(EXIT_FAILURE);
}
int main(int argc, char *argv[]) {
int length = -1, times = -1;
bool dosync = false;
int opt;
while ((opt = getopt(argc, argv, "l:t:s")) != -1) {
if (opt == 'l')
length = atoi(optarg);
else if (opt == 't')
times = atoi(optarg);
else if (opt == 's')
dosync = true;
else
usage(argc, argv);
}
if (optind >= argc || length <= 0 || times <= 0)
usage(argc, argv);
char *choice = argv[optind];
char *line = malloc(length + 1);
memset(line, '*', length);
line[length] = '\n';
if (strcmp(choice, "write") == 0) {
for (int j = 0; j < times; j++)
for (int k = 0; k < length; k++)
write(STDOUT_FILENO, line + k, length + 1 - k);
}
if (strncmp(choice, "fwrite", 6) == 0) {
size_t size;
int mode;
void *buf;
if (strcmp(choice, "fwrite-line") == 0) {
mode = _IOLBF;
size = length + 1;
} else if (strcmp(choice, "fwrite-full") == 0) {
mode = _IOFBF;
size = getpagesize();
} else {
mode = _IONBF;
size = 0;
}
buf = malloc(size + 1);
/* TODO: Attach new buffer to stdout stream. */
setvbuf(stdout, buf, mode, size);
for (int j = 0; j < times; j++)
for (int k = 0; k < length; k++)
fwrite(line + k, length + 1 - k, 1, stdout);
fflush(stdout);
free(buf);
}
if (strcmp(choice, "writev") == 0) {
int n = sysconf(_SC_IOV_MAX);
struct iovec iov[n];
/* TODO: Write file by filling in iov array and issuing writev. */
for (int k = 0; k < length; k++) {
iov[k].iov_base = line + k;
iov[k].iov_len = length + 1 - k;
}
for (int j = 0; j < times; j++)
Writev(1, iov, length);
}
free(line);
if (dosync && !isatty(STDOUT_FILENO))
fsync(STDOUT_FILENO);
return 0;
}
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