mountp.c

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/mount.h>

char *options;
size_t buflen = (_POSIX_MAX_INPUT+1) * 2;
uint32_t mntflags;

void
append_option(uint32_t flag, char *option_yes, char *option_no)
{
	if ((mntflags & flag) && option_yes != NULL) {
		if (*options != '\0')
			strlcat(options, ",", buflen);
		strlcat(options, option_yes, buflen);
	} else if (!(mntflags & flag) && option_no != NULL) {
		if (*options != '\0')
			strlcat(options, ",", buflen);
		strlcat(options, option_no, buflen);
	}
}

int main(int argc, char *argv[]) {
	options = (char *)malloc(buflen);
	options[0] = '\0';
	struct statfs *mounts;
	int num_mounts = getmntinfo(&mounts, MNT_WAIT);
	for (int i = 0; i < num_mounts; i++) {
		mntflags = mounts[i].f_flags;
		append_option(MNT_LOCAL, "local", NULL);
		append_option(MNT_RDONLY, "ro", "rw");
		append_option(MNT_JOURNALED, "journaled", NULL);
		append_option(MNT_NOEXEC, "noexec", NULL);
		append_option(MNT_NOSUID, "nosuid", NULL);
		append_option(MNT_NODEV, "nodev", NULL);
		append_option(MNT_DONTBROWSE, "nobrowse", NULL);
		append_option(MNT_IGNORE_OWNERSHIP, "noowners", NULL);
		append_option(MNT_NOUSERXATTR, "noxattr", NULL);
		append_option(MNT_NOATIME, "noatime", NULL);
		printf("%s\t%s\t%s\t%s\n", mounts[i].f_mntfromname,
		    mounts[i].f_mntonname, mounts[i].f_fstypename, options);
		options[0] = '\0';
	}
	free(options);
}