man2/statvfs.2

   1 .\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl)
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  23 .\" The pathconf note is from Walter Harms
  24 .\" This is not a system call on Linux
  25 .\"
  26 .\" Modified 2004-06-23 by Michael Kerrisk <mtk16@ext.canterbury.ac.nz>
  27 .\"
  28 .TH STATVFS 2 2003-08-22 "Linux 2.6.0" "Linux Programmer's Manual"
  29 .SH NAME
  30 statvfs, fstatvfs \- get file system statistics
  31 .SH SYNOPSIS
  32 .B #include <sys/statvfs.h>
  33 .sp
  34 .BI "int statvfs(const char *" path ", struct statvfs *" buf );
  35 .br
  36 .BI "int fstatvfs(int " fd ", struct statvfs *" buf );
  37 .SH DESCRIPTION
  38 The function
  39 .B statvfs
  40 returns information about a mounted file system.
  41 .I path
  42 is the path name of any file within the mounted filesystem.
  43 .I buf
  44 is a pointer to a
  45 .I statvfs
  46 structure defined approximately as follows:
  47
  48 .nf
  49   struct statvfs {
  50     unsigned long  f_bsize;    /* file system block size */
  51     unsigned long  f_frsize;   /* fragment size */
  52     fsblkcnt_t     f_blocks;   /* size of fs in f_frsize units */
  53     fsblkcnt_t     f_bfree;    /* # free blocks */
  54     fsblkcnt_t     f_bavail;   /* # free blocks for non-root */
  55     fsfilcnt_t     f_files;    /* # inodes */
  56     fsfilcnt_t     f_ffree;    /* # free inodes */
  57     fsfilcnt_t     f_favail;   /* # free inodes for non-root */
  58     unsigned long  f_fsid;     /* file system id */
  59     unsigned long  f_flag;     /* mount flags */
  60     unsigned long  f_namemax;  /* maximum filename length */
  61   };
  62 .fi
  63
  64 Here the types
  65 .B fsblkcnt_t
  66 and
  67 .B fsfilcnt_t
  68 are defined in
  69 .IR <sys/types.h> .
  70 Both used to be
  71 .BR "unsigned long" .
  72
  73 The field
  74 .I f_flag
  75 is a bit mask (of mount flags, see
  76 .BR mount (8)).
  77 Bits defined by POSIX are
  78 .TP
  79 .B ST_RDONLY
  80 Read-only file system.
  81 .TP
  82 .B ST_NOSUID
  83 Setuid/setgid bits are ignored by
  84 .BR exec (2).
  85 .LP
  86
  87 It is unspecified whether all members of the returned struct
  88 have meaningful values on all filesystems.
  89
  90 .B fstatvfs
  91 returns the same information about an open file referenced by descriptor
  92 .IR fd .
  93 .SH "RETURN VALUE"
  94 On success, zero is returned.  On error, \-1 is returned, and
  95 .I errno
  96 is set appropriately.
  97 .SH ERRORS
  98 .TP
  99 .B EACCES
 100 (statvfs)
 101 Search permission is denied for a component of the path prefix of
 102 .IR path .
 103 (See also
 104 .BR path_resolution (2).)
 105 .TP
 106 .B EBADF
 107 (fstatvfs)
 108 .I fd
 109 is not a valid open file descriptor.
 110 .TP
 111 .B EFAULT
 112 .I Buf
 113 or
 114 .I path
 115 points to an invalid address.
 116 .TP
 117 .B EINTR
 118 This call was interrupted by a signal.
 119 .TP
 120 .B EIO
 121 An I/O error occurred while reading from the file system.
 122 .TP
 123 .B ELOOP
 124 (statvfs)
 125 Too many symbolic links were encountered in translating
 126 .IR path .
 127 .TP
 128 .B ENAMETOOLONG
 129 (statvfs)
 130 .I path
 131 is too long.
 132 .TP
 133 .B ENOENT
 134 (statvfs)
 135 The file referred to by
 136 .I path
 137 does not exist.
 138 .TP
 139 .B ENOMEM
 140 Insufficient kernel memory was available.
 141 .TP
 142 .B ENOSYS
 143 The file system does not support this call.
 144 .TP
 145 .B ENOTDIR
 146 (statvfs)
 147 A component of the path prefix of
 148 .I path
 149 is not a directory.
 150 .TP
 151 .B EOVERFLOW
 152 Some values were too large to be represented in the returned struct.
 153 .PP
 154 .SH "CONFORMING TO"
 155 Solaris, Irix, POSIX 1003.1-2001
 156 .SH NOTES
 157 The Linux kernel has system calls statfs, fstatfs
 158 to support this library call.
 159
 160 The current glibc implementation of
 161 .sp
 162 .nf
 163    pathconf(path, _PC_REC_XFER_ALIGN);
 164    pathconf(path, _PC_ALLOC_SIZE_MIN);
 165    pathconf(path, _PC_REC_MIN_XFER_SIZE);
 166 .fi
 167 .sp
 168 uses the
 169 .IR f_frsize ,
 170 .IR f_frsize ,
 171 and
 172 .IR f_bsize
 173 fields of the return value of
 174 .IR "statvfs(path,buf)" .
 175 .SH "SEE ALSO"
 176 .BR statfs (2)