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| #define _GNU_SOURCE // 启用 GNU 扩展
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/vfs.h> // 包含 statfs
#include <sys/statvfs.h> // 包含 statvfs
#include <string.h>
#include <errno.h>
#include <fcntl.h> // 包含 open
// 辅助函数：打印人类可读的大小
void print_human_readable(double bytes, const char* prefix) {
const char *units[] = {"B", "KiB", "MiB", "GiB", "TiB"};
int unit_index = 0;
double size_to_print = bytes;
while (size_to_print >= 1024 && unit_index < 4) {
size_to_print /= 1024;
unit_index++;
}
printf("%s%.2f %s", prefix, size_to_print, units[unit_index]);
}
// 使用 statfs 打印信息
void print_fs_info_statfs(const char* path, const struct statfs *sfs) {
printf("=== Filesystem information for '%s' (via statfs) ===\n", path);
printf(" Optimal I/O Block Size: %ld bytes\n", (long)sfs->f_bsize);
printf(" Fragment Size: %ld bytes\n", (long)sfs->f_frsize);
printf(" Total Fragments: %ld\n", (long)sfs->f_blocks);
printf(" Free Fragments: %ld\n", (long)sfs->f_bfree);
printf(" Available Fragments: %ld (for non-root users)\n", (long)sfs->f_bavail);
printf(" Total Inodes: %ld\n", (long)sfs->f_files);
printf(" Free Inodes: %ld\n", (long)sfs->f_ffree);
printf(" Filesystem ID: %d:%d\n", (int)sfs->f_fsid.__val[0], (int)sfs->f_fsid.__val[1]);
printf(" Maximum Filename Length: %ld\n", (long)sfs->f_namelen);
printf(" Mount Flags: 0x%lx\n", (unsigned long)sfs->f_flags);
// 计算并打印人类可读的空间大小
double total_bytes = (double)sfs->f_blocks * sfs->f_frsize;
double free_bytes = (double)sfs->f_bfree * sfs->f_frsize;
double avail_bytes = (double)sfs->f_bavail * sfs->f_frsize;
printf(" Total Size: ");
print_human_readable(total_bytes, "");
printf("\n");
printf(" Available Size: ");
print_human_readable(avail_bytes, "");
printf("\n");
// 识别文件系统类型 (仅列举几个常见类型)
switch (sfs->f_type) {
case 0xEF53: // EXT2/3/4
printf(" Filesystem Type: ext2/ext3/ext4\n");
break;
case 0x6969: // NFS
printf(" Filesystem Type: NFS\n");
break;
case 0x517B: // SMB/CIFS
printf(" Filesystem Type: SMB/CIFS\n");
break;
case 0x52654973: // ReiserFS
printf(" Filesystem Type: ReiserFS\n");
break;
case 0x5346544E: // NTFS
printf(" Filesystem Type: NTFS\n");
break;
case 0x4d44: // FAT
printf(" Filesystem Type: FAT\n");
break;
case 0x01021994: // TMPFS
printf(" Filesystem Type: tmpfs\n");
break;
case 0x9123683E: // Btrfs
printf(" Filesystem Type: Btrfs\n");
break;
default:
printf(" Filesystem Type: Unknown (Magic: 0x%lx)\n", (unsigned long)sfs->f_type);
break;
}
printf("\n");
}
// 使用 statvfs 打印信息
void print_fs_info_statvfs(const char* path, const struct statvfs *svfs) {
printf("=== Filesystem information for '%s' (via statvfs) ===\n", path);
printf(" Filesystem Block Size: %ld bytes\n", (long)svfs->f_bsize);
printf(" Fragment Size: %ld bytes\n", (long)svfs->f_frsize);
printf(" Total Fragments: %ld\n", (long)svfs->f_blocks);
printf(" Free Fragments: %ld\n", (long)svfs->f_bfree);
printf(" Available Fragments: %ld (for non-root users)\n", (long)svfs->f_bavail);
printf(" Available Fragments (non-root): %ld\n", (long)svfs->f_bavail); // Same as f_bavail in most cases
printf(" Total Inodes: %ld\n", (long)svfs->f_files);
printf(" Free Inodes: %ld\n", (long)svfs->f_ffree);
printf(" Available Inodes (non-root): %ld\n", (long)svfs->f_favail);
printf(" Filesystem ID: %ld\n", (unsigned long)svfs->f_fsid);
printf(" Maximum Filename Length: %ld\n", (long)svfs->f_namemax);
printf(" Mount Flags: 0x%lx\n", svfs->f_flag);
// 计算并打印人类可读的空间大小
double total_bytes = (double)svfs->f_blocks * svfs->f_frsize;
double free_bytes = (double)svfs->f_bfree * svfs->f_frsize;
double avail_bytes = (double)svfs->f_bavail * svfs->f_frsize;
printf(" Total Size: ");
print_human_readable(total_bytes, "");
printf("\n");
printf(" Available Size: ");
print_human_readable(avail_bytes, "");
printf("\n");
printf("\n");
}
int main(int argc, char *argv[]) {
struct statfs sfs;
struct statvfs svfs;
int fd;
printf("--- Demonstrating statfs vs statvfs ---\n");
// 1. 如果没有提供命令行参数，则查询根目录 "/"
const char *path = "/";
if (argc > 1) {
path = argv[1];
}
printf("Querying path: '%s'\n\n", path);
// 2. 使用 statfs 查询
if (statfs(path, &sfs) == 0) {
print_fs_info_statfs(path, &sfs);
} else {
printf("statfs failed for '%s': %s\n\n", path, strerror(errno));
}
// 3. 使用 statvfs 查询
if (statvfs(path, &svfs) == 0) {
print_fs_info_statvfs(path, &svfs);
} else {
printf("statvfs failed for '%s': %s\n\n", path, strerror(errno));
}
// 4. 演示 fstatfs 和 fstatvfs (通过文件描述符)
printf("=== Comparing fstatfs and fstatvfs ===\n");
fd = open(path, O_RDONLY); // 尝试打开路径 (对于目录是合法的)
if (fd != -1) {
printf("Opened '%s' as file descriptor %d\n", path, fd);
if (fstatfs(fd, &sfs) == 0) {
printf("\n--- fstatfs via fd %d ---\n", fd);
printf(" Total Fragments (fstatfs): %ld\n", (long)sfs.f_blocks);
printf(" Free Fragments (fstatfs): %ld\n", (long)sfs.f_bfree);
} else {
printf("fstatfs failed: %s\n", strerror(errno));
}
if (fstatvfs(fd, &svfs) == 0) {
printf("\n--- fstatvfs via fd %d ---\n", fd);
printf(" Total Fragments (fstatvfs): %ld\n", (long)svfs.f_blocks);
printf(" Free Fragments (fstatvfs): %ld\n", (long)svfs.f_bfree);
} else {
printf("fstatvfs failed: %s\n", strerror(errno));
}
close(fd);
} else {
// 如果打开失败（例如 path 是文件），尝试打开文件本身
fd = open(path, O_RDONLY);
if (fd != -1) {
printf("Opened file '%s' as file descriptor %d\n", path, fd);
// ... (对文件进行 fstatfs/fstatvfs 调用)
// 为简洁起见，此处省略对文件的详细查询，逻辑同上
close(fd);
} else {
printf("Could not open '%s' as file/dir for fstatfs/fstatvfs demo.\n", path);
}
}
// 5. 演示一个实际应用：检查磁盘空间是否充足
printf("\n=== Checking Disk Space ===\n");
const char *check_path = "/tmp"; // 检查 /tmp 分区
if (statvfs(check_path, &svfs) == 0) {
double avail_bytes = (double)svfs.f_bavail * svfs.f_frsize;
double required_bytes = 100 * 1024 * 1024; // 假设需要 100MB
printf("Checking if '%s' has at least %.2f MiB available...\n",
check_path, required_bytes / (1024.0*1024.0));
if (avail_bytes >= required_bytes) {
printf("OK: ");
print_human_readable(avail_bytes, "");
printf(" available, %.2f MiB required.\n", required_bytes / (1024.0*1024.0));
} else {
printf("WARNING: Only ");
print_human_readable(avail_bytes, "");
printf(" available, %.2f MiB required. Insufficient space!\n", required_bytes / (1024.0*1024.0));
}
} else {
perror("statvfs for space check");
}
return 0;
}
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