Other system calls. More...

Functions
int	soOpenFileSystem (const char *devname)
	Open the sofs19 file system. More...

int	soCloseFileSystem (void)
	Close the sofs19 file system. More...

int	soStatFS (const char path, struct statvfs st)
	Get file system statistics. More...

int	soStat (const char path, struct stat st)
	Get file status. More...

int	soAccess (const char *path, int opRequested)
	Check real user's permissions for a file. More...

int	soChmod (const char *path, mode_t mode)
	Change permissions of a file. More...

int	soChown (const char *path, uid_t owner, gid_t group)
	Change the ownership of a file. More...

int	soUtime (const char path, const struct utimbuf times)
	Change the last access and modification times of a file. More...

int	soUtimens (const char *path, const struct timespec tv[2])
	Change the last access and modification times of a file with nanosecond resolution. More...

int	soOpen (const char *path, int flags)
	Open a regular file. More...

int	soClose (const char *path)
	Close a regular file. More...

int	soFsync (const char *path)
	Synchronize a file's in-core state with storage device. More...

int	soOpendir (const char *path)
	Open a directory for reading. More...

int	soClosedir (const char *path)
	Close a directory. More...

Detailed Description

Other system calls.

Function Documentation

◆ soOpenFileSystem()

int sofs19::soOpenFileSystem ( const char * devname )

Open the sofs19 file system.

The rawdisk is open and, if it does not fail, the three dealers are open. This function is called by the mount operation.

Parameters

devname absolute path to the Linux file that simulates the storage device

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soCloseFileSystem()

int sofs19::soCloseFileSystem ( void )

Close the sofs19 file system.

The three dealers are closed and then the raw disk is closed. This function is called by the unmount operation.

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soStatFS()

int sofs19::soStatFS	(	const char *	path,
		struct statvfs *	st
	)

Get file system statistics.

It tries to emulate statvfs system call.

Information about a mounted file system is returned. It checks whether the calling process can access the file specified by the path.

To get more information, execute in a terminal the command man 2 statvfs

Parameters

path	path to any file within the mounted file system
st	pointer to a statvfs structure

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soStat()

int sofs19::soStat	(	const char *	path,
		struct stat *	st
	)

Get file status.

It tries to emulate stat system call.

Information about a specific file is returned. It checks whether the calling process can access the file specified by the path.

To get more information, execute in a terminal the command man 2 stat

Parameters

path	path to the file
st	pointer to a stat structure

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soAccess()

int sofs19::soAccess	(	const char *	path,
		int	opRequested
	)

Check real user's permissions for a file.

It tries to emulate access system call.

It checks whether the calling process can access the file specified by the path for the requested operation.

To get more information, execute in a terminal the command man 2 access

Parameters

path	path to the file
opRequested	operation to be performed: F_OK (check if file exists) a bitwise combination of R_OK, W_OK, and X_OK

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soChmod()

int sofs19::soChmod	(	const char *	path,
		mode_t	mode
	)

Change permissions of a file.

It tries to emulate chmod system call.

It changes the permissions of a file specified by the path.

Remarks: If the file is a symbolic link, its contents shall always be used to reach the destination file, so the permissions of a symbolic link can never be changed (they are set to rwx for user, group and other when the link is created and remain unchanged thereafter).

To get more information, execute in a terminal the command man 2 chmod

Parameters

path	path to the file
mode	permissions to be set: a bitwise combination of S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soChown()

int sofs19::soChown	(	const char *	path,
		uid_t	owner,
		gid_t	group
	)

Change the ownership of a file.

It tries to emulate chown system call.

It changes the ownership of the file specified by the path.

Only root may change the owner of a file. The file's owner may change the group if the specified group is one of the owner's supplementary groups.

To get more information, execute in a terminal the command man 2 chown

Parameters

path	path to the file
owner	file user id (-1, if user is not to be changed)
group	file group id (-1, if group is not to be changed)

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soUtime()

int sofs19::soUtime	(	const char *	path,
		const struct utimbuf *	times
	)

Change the last access and modification times of a file.

It tries to emulate utime system call.

To get more information, execute in a terminal the command man 2 utime

Parameters

path	path to the file
times	pointer to a structure where the last access and modification times are passed, if `NULL`, the last access and modification times are set to the current time

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soUtimens()

int sofs19::soUtimens	(	const char *	path,
		const struct timespec	tv[2]
	)

Change the last access and modification times of a file with nanosecond resolution.

It tries to emulate utimensat system call.

To get more information, execute in a terminal the command man 2 utimensat

Parameters

path path to the file

tv structure array where the last access, element of index 0, and modification, element of index 1, times are passed, if NULL, the last access and modification times are set to the current time if the tv_nsec field of one of the timespec structures has the special value UTIME_NOW, then the corresponding file timestamp is set to the current time if the tv_nsec field of one of the timespec structures has the special value UTIME_OMIT, then the corresponding file timestamp is left unchanged

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soOpen()

int sofs19::soOpen	(	const char *	path,
		int	flags
	)

Open a regular file.

It tries to emulate open system call.

In the current implementation it only checks if the calling process can access the file for the openning operation.

To get more information, execute in a terminal the command man 2 open

Parameters

path	path to the file
flags	access modes to be used: O_RDONLY, O_WRONLY, O_RDWR

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soClose()

int sofs19::soClose ( const char * path )

Close a regular file.

It tries to emulate close system call.

To get more information, execute in a terminal the command man 2 close

Parameters

path	path to the file

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soFsync()

int sofs19::soFsync ( const char * path )

Synchronize a file's in-core state with storage device.

It tries to emulate fsync system call.

To get more information, execute in a terminal the command man 2 fsync

Parameters

path	path to the file

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure; 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soOpendir()

int sofs19::soOpendir ( const char * path )

Open a directory for reading.

It tries to emulate opendir system call. In the current implementation it only checks if the calling process can access the file for the openning operation.

To get more information, execute in a terminal the command man opendir

Parameters

path	path to the file

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

◆ soClosedir()

int sofs19::soClosedir ( const char * path )

Close a directory.

It tries to emulate closedir system call.

To get more information, execute in a terminal the command man closedir

Parameters

path	path to the file

Returns: 0 on success; -errno in case of error, being errno the system error that better represents the cause of failure

Functions

Detailed Description

Function Documentation

◆ soOpenFileSystem()

◆ soCloseFileSystem()

◆ soStatFS()

◆ soStat()

◆ soAccess()

◆ soChmod()

◆ soChown()

◆ soUtime()

◆ soUtimens()

◆ soOpen()

◆ soClose()

◆ soFsync()

◆ soOpendir()

◆ soClosedir()