Files
Compsys-2021-Assignments/A2/fauxgrep-mt.c
Nikolaj a988405fd3 A3 🎉
2021-10-26 14:15:16 +02:00

88 lines
2.0 KiB
C

// Setting _DEFAULT_SOURCE is necessary to activate visibility of
// certain header file contents on GNU/Linux systems.
#define _DEFAULT_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fts.h>
// err.h contains various nonstandard BSD extensions, but they are
// very handy.
#include <err.h>
#include <pthread.h>
#include "job_queue.h"
int main(int argc, char * const *argv) {
if (argc < 2) {
err(1, "usage: [-n INT] STRING paths...");
exit(1);
}
int num_threads = 1;
char const *needle = argv[1];
char * const *paths = &argv[2];
if (argc > 3 && strcmp(argv[1], "-n") == 0) {
// Since atoi() simply returns zero on syntax errors, we cannot
// distinguish between the user entering a zero, or some
// non-numeric garbage. In fact, we cannot even tell whether the
// given option is suffixed by garbage, i.e. '123foo' returns
// '123'. A more robust solution would use strtol(), but its
// interface is more complicated, so here we are.
num_threads = atoi(argv[2]);
if (num_threads < 1) {
err(1, "invalid thread count: %s", argv[2]);
}
needle = argv[3];
paths = &argv[4];
} else {
needle = argv[1];
paths = &argv[2];
}
assert(0); // Initialise the job queue and some worker threads here.
// FTS_LOGICAL = follow symbolic links
// FTS_NOCHDIR = do not change the working directory of the process
//
// (These are not particularly important distinctions for our simple
// uses.)
int fts_options = FTS_LOGICAL | FTS_NOCHDIR;
FTS *ftsp;
if ((ftsp = fts_open(paths, fts_options, NULL)) == NULL) {
err(1, "fts_open() failed");
return -1;
}
FTSENT *p;
while ((p = fts_read(ftsp)) != NULL) {
switch (p->fts_info) {
case FTS_D:
break;
case FTS_F:
assert(0); // Process the file p->fts_path, somehow.
break;
default:
break;
}
}
fts_close(ftsp);
assert(0); // Shut down the job queue and the worker threads here.
return 0;
}