A mix of Rust and C language

There is a memory leak

extern Crate libc;use libc::size_t;use libc::{file,c_char};use std:: String;#[repr (C)]pub struct mntent {mnt_fsname:* mut c_char,/* Name of mounted file system */Mnt_dir:* Mut C_char,/* mount point * /Mnt_type:* Mut c_char,/* File system Type: UFS, NFS etc */mnt_opts:* Mut c_char,/* option, comma delimiter */mnt_freq:size_t ,/* The frequency of the Dump (in days) */mnt_passno:size_t,/* fsck Check order */}#[link (name = "Diskstat", kind= "static")]ext    Ern "C" {fn getdisk (), *const C_char;    PUB fn setmntent (filename: *const c_char, Ttype: *const C_char), FILE;    PUB fn getmntent (filep:file), mntent; PUB fn endmntent (filep:file), size_t;}    fn Main () {let mut mnt = unsafe {(Setmntent ("/etc/mtab". To_c_str (). As_ptr (), "R". To_c_str (). As_ptr ())};    Let Mut disk_info = unsafe {string::raw::from_buf (Getdisk () as *const U8)}; println! ("{}", disk_info);} <!--lang:cpp--> 

//Gcc-c Diskstat.c-o diskstat.o-fpic
//ar-r libdiskstat.a DISKSTAT.O

#include <stdio.h> #include <mntent.h> #include <string.h> #include <sys/vfs.h> static const u  nsigned Long Long G = 1024*1024*1024ull;  Static const unsigned long long M = 1024*1024;  Static const unsigned long long K = 1024;  static Char str[20];      char* Kscale (unsigned long b, unsigned long BS) {unsigned long long size = b * (unsigned long long) BS;          if (Size > G) {sprintf (str, "%0.2f GB", size/(g*1.0));      return str;          } else if (Size > M) {sprintf (str, "%0.2f MB", size/(1.0*m));      return str;          } else if (Size > k) {sprintf (str, "%0.2f K", size/(1.0*k));      return str;          } else {sprintf (str, "%0.2f B", size*1.0);      return str;      }}char* Getdisk () {file* mount_table;      struct Mntent *mount_entry;      struct STATFS s;      unsigned long blocks_used;      unsigned blocks_percent_used; const CHAR *DISP_UNITS_HDR = NULL;      mount_table = NULL;      mount_table = Setmntent ("/etc/mtab", "R");          if (!mount_table) {fprintf (stderr, "Set Mount Entry error\n");      return-1;      } DISP_UNITS_HDR = "Size";      printf ("Filesystem%-15sused Available%s mounted on\n",//Disp_units_hdr, "use%");    Char *disk_info = (char *) malloc (10000*sizeof (char)); strcpy (Disk_info, "[");    A//*disk_info = "[";    Char *z = (char *) malloc (1000*sizeof (char));          while (1) {const char *device;          const char *mount_point;        const char *fs_type;              if (mount_table) {mount_entry = Getmntent (mount_table);                  if (!mount_entry) {endmntent (mount_table);              Break          }} else continue;          device = mount_entry->mnt_fsname;          Mount_point = mount_entry->mnt_dir;        Fs_type = mount_entry->mnt_type; //fprintf (stderr, "Error Mount info:device=%s mountpoint=%s\n", device, Mount_point);                  if (Statfs (Mount_point, &s)! = 0) {fprintf (stderr, "Statfs failed!\n");          Continue              } if ((S.f_blocks > 0) | | |!mount_table) {blocks_used = S.f_blocks-s.f_bfree;              blocks_percent_used = 0;                          if (blocks_used + s.f_bavail) {blocks_percent_used = (blocks_used * 100ULL              + (blocks_used + s.f_bavail)/2)/(blocks_used + s.f_bavail);              } if (strcmp (device, "rootfs") = = 0) continue;              if (printf ("Hello dksks \n%-20s" + 1, Device) >)//printf ("\n%-20s", "");              Char s1[20];              Char s2[20];              Char s3[20];              strcpy (S1, Kscale (S.f_blocks, s.f_bsize)); strcpy (S2, Kscale (s.f_blocks-S.f_bfree, s.f_bsize));              strcpy (S3, Kscale (S.f_bavail, s.f_bsize)); sprintf (z, "{\" device\ ": \"%s\ ", \" fs_type\ ": \"%s\ ", \" mount_point\ ": \"%s\ ", \" size\ ": \"%s\ ", \" used\ ":%s,\"                    Available\ ": \"%s\ ", \" use_percent\ ": \"%3u%%\ "},", Device, Fs_type,             Mount_point, S1, S2, S3, blocks_percent_used             );        Strncat (disk_info,z, 1000);    }} strncat (Disk_info, "]", 1); return disk_info;}

One-time Rust and C-language mashup