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| .\" Created Wed Aug 9 1995 Thomas K. Dyas <tdyas@eden.rutgers.edu> |
| .\" |
| .TH SYSFS 2 2021-03-22 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| sysfs \- get filesystem type information |
| .SH SYNOPSIS |
| .nf |
| .BI "int sysfs(int " option ", const char *" fsname ); |
| .BI "int sysfs(int " option ", unsigned int " fs_index ", char *" buf ); |
| .BI "int sysfs(int " option ); |
| .fi |
| .SH DESCRIPTION |
| .BR "Note" : |
| if you are looking for information about the |
| .B sysfs |
| filesystem that is normally mounted at |
| .IR /sys , |
| see |
| .BR sysfs (5). |
| .PP |
| The (obsolete) |
| .BR sysfs () |
| system call returns information about the filesystem types |
| currently present in the kernel. |
| The specific form of the |
| .BR sysfs () |
| call and the information returned depends on the |
| .I option |
| in effect: |
| .TP 3 |
| .B 1 |
| Translate the filesystem identifier string |
| .I fsname |
| into a filesystem type index. |
| .TP |
| .B 2 |
| Translate the filesystem type index |
| .I fs_index |
| into a null-terminated filesystem identifier string. |
| This string will |
| be written to the buffer pointed to by |
| .IR buf . |
| Make sure that |
| .I buf |
| has enough space to accept the string. |
| .TP |
| .B 3 |
| Return the total number of filesystem types currently present in the |
| kernel. |
| .PP |
| The numbering of the filesystem type indexes begins with zero. |
| .SH RETURN VALUE |
| On success, |
| .BR sysfs () |
| returns the filesystem index for option |
| .BR 1 , |
| zero for option |
| .BR 2 , |
| and the number of currently configured filesystems for option |
| .BR 3 . |
| On error, \-1 is returned, and |
| .I errno |
| is set to indicate the error. |
| .SH ERRORS |
| .TP |
| .B EFAULT |
| .RI "Either " fsname " or " buf |
| is outside your accessible address space. |
| .TP |
| .B EINVAL |
| .I fsname |
| is not a valid filesystem type identifier; |
| .I fs_index |
| is out-of-bounds; |
| .I option |
| is invalid. |
| .SH CONFORMING TO |
| SVr4. |
| .SH NOTES |
| This System-V derived system call is obsolete; don't use it. |
| On systems with |
| .IR /proc , |
| the same information can be obtained via |
| .IR /proc ; |
| use that interface instead. |
| .SH BUGS |
| There is no libc or glibc support. |
| There is no way to guess how large \fIbuf\fP should be. |
| .SH SEE ALSO |
| .BR proc (5), |
| .BR sysfs (5) |