| .\" Copyright (C) 1995, Thomas K. Dyas <tdyas@eden.rutgers.edu> |
| .\" |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
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| .\" Created 1995-08-09 Thomas K. Dyas <tdyas@eden.rutgers.edu> |
| .\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com> |
| .\" Modified 2001-03-22 by aeb |
| .\" Modified 2003-08-04 by aeb |
| .\" |
| .TH USTAT 2 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| ustat \- get filesystem statistics |
| .SH SYNOPSIS |
| .nf |
| .B #include <sys/types.h> |
| .BR "#include <unistd.h>" " /* libc[45] */" |
| .BR "#include <ustat.h>" " /* glibc2 */" |
| .PP |
| .BI "int ustat(dev_t " dev ", struct ustat *" ubuf ); |
| .fi |
| .SH DESCRIPTION |
| .BR ustat () |
| returns information about a mounted filesystem. |
| .I dev |
| is a device number identifying a device containing |
| a mounted filesystem. |
| .I ubuf |
| is a pointer to a |
| .I ustat |
| structure that contains the following |
| members: |
| .PP |
| .in +4n |
| .EX |
| daddr_t f_tfree; /* Total free blocks */ |
| ino_t f_tinode; /* Number of free inodes */ |
| char f_fname[6]; /* Filsys name */ |
| char f_fpack[6]; /* Filsys pack name */ |
| .EE |
| .in |
| .PP |
| The last two fields, |
| .I f_fname |
| and |
| .IR f_fpack , |
| are not implemented and will |
| always be filled with null bytes (\(aq\e0\(aq). |
| .SH RETURN VALUE |
| On success, zero is returned and the |
| .I ustat |
| structure pointed to by |
| .I ubuf |
| will be filled in. |
| On error, \-1 is returned, and |
| .I errno |
| is set to indicate the error. |
| .SH ERRORS |
| .TP |
| .B EFAULT |
| .I ubuf |
| points outside of your accessible address space. |
| .TP |
| .B EINVAL |
| .I dev |
| does not refer to a device containing a mounted filesystem. |
| .TP |
| .B ENOSYS |
| The mounted filesystem referenced by |
| .I dev |
| does not support this operation, or any version of Linux before |
| 1.3.16. |
| .SH VERSIONS |
| Since version 2.28, glibc no longer provides a wrapper for this system call. |
| .SH CONFORMING TO |
| SVr4. |
| .\" SVr4 documents additional error conditions ENOLINK, ECOMM, and EINTR |
| .\" but has no ENOSYS condition. |
| .SH NOTES |
| .BR ustat () |
| is deprecated and has been provided only for compatibility. |
| All new programs should use |
| .BR statfs (2) |
| instead. |
| .SS HP-UX notes |
| The HP-UX version of the |
| .I ustat |
| structure has an additional field, |
| .IR f_blksize , |
| that is unknown elsewhere. |
| HP-UX warns: |
| For some filesystems, the number of free inodes does not change. |
| Such filesystems will return \-1 in the field |
| .IR f_tinode . |
| .\" Some software tries to use this in order to test whether the |
| .\" underlying filesystem is NFS. |
| For some filesystems, inodes are dynamically allocated. |
| Such filesystems will return the current number of free inodes. |
| .SH SEE ALSO |
| .BR stat (2), |
| .BR statfs (2) |
