Get the options that a filesystem was mounted with
#include <sys/dcmd_blk.h> #define DCMD_FSYS_OPTIONS __DIOF(_DCMD_FSYS, 19, char[256])
Argument | Value |
---|---|
filedes | A file descriptor that you obtained by opening the device. |
dcmd | DCMD_FSYS_OPTIONS |
dev_data_ptr | A char[256] buffer |
n_bytes | The size of the buffer |
dev_info_ptr | NULL |
This command gets the command-line options that the given filesystem was mounted with. The df utility uses this command if you specify the -g option.
None.
A null-terminated string that contains the command-line arguments.
The devctl() function can return the following, in addition to the error codes listed in its entry in the C Library Reference:
char o[265]; int fd, err; if(-1 == (fd = open(argv[1] ? argv[1] : "/", O_RDONLY))) { perror ("Couldn't open the device"); return EXIT_FAILURE; } memset(o, 0, sizeof(o)); if((err = devctl(fd, DCMD_FSYS_OPTIONS, o, sizeof(o), 0)) != EOK) { o[0] = '\0'; printf("Couldn't get the options: %s (%d)\n", strerror(err), err); } else { printf("Fsys options: \"%s\"\n", o); }
devctl() in the QNX Neutrino C Library Reference