File

Interface for basic file and directory operations.

File information

Classes

class FileSystem {
public:
    static class IFileWrite * OpenWriteFile(const char * fileName, bool append, class IInstanceLog * log);
    static class IFileRead * OpenReadFile(const char * fileName, class IInstanceLog * log);
    static class IDirectory * OpenDirectory(const char * directoryName, class IInstanceLog * log);
    static class IElfBinary * OpenElfBinary(const char * bin, class IInstanceLog * log);
    static bool ReadWholeFile(const char * filename, char * readBuffer, size_t size, class IInstanceLog * log);
    static bool WriteWholeFile(const char * filename, const char * writeBuffer, size_t size, class IInstanceLog * log);
    static bool ScanFile(class IInstanceLog * log, const char * filename, const char * format, ...);
    static bool FileExists(const char * filename, class IInstanceLog * log);
    static time_t GetLastWriteTime(const char * filename, class IInstanceLog * log);
    static off_t GetFileSize(const char * filename, class IInstanceLog * log);
    static off_t GetFileBlockSize(const char * filename, class IInstanceLog * log);
    static bool Rename(const char * oldName, const char * newName, class IInstanceLog * log);
    static bool RemoveFile(const char * filename, class IInstanceLog * log);
    static bool CreateDirectory(const char * absolutePath, int mode, class IInstanceLog * log);
    static bool RemoveDirectory(const char * directoryPath, class IInstanceLog * log);
    static bool ChangeOwner(const char * path, const char * newOwner, const char * newGroup, class IInstanceLog * log);
    static bool ChangeMode(const char * path, int mode, class IInstanceLog * log);
    static ulong64 GetFileSystemTotalSize(const char * path, class IInstanceLog * log);
    static ulong64 GetFileSystemUsedSpace(const char * path, class IInstanceLog * log);
    static bool CheckSystemUser(const char * user, const char * group, class IInstanceLog * log);
    static char * GetFileSystemUser(const char * filepath, class IInstanceLog * log);
};

Overview

Logging

Public functions

The main function to use to open a file for write operation. An empty file is created and opened for writinf if append is false; otherwise the file is opened for the writing at the end of the file. If the file is opened successfully, an object of class IFileWrite is returned. In case of error, a null pointer is returned.

Parameters

const char * fileName	The absolute full path of the file
bool append	Specifies whether a file is to be opened for append oor write operation
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

The IFileWrite instance created. It must be freed by the C++ operator delete, if no longer needed.

Code Example

class IFileWrite * file = FileSystem::OpenWriteFile("/path/file.txt", false, log_instance);
if(file) {
....
  write operation
...
delete file;
}
                

The main function to open an exisitng file for a read operation. On success, an object of the class IFileRead is returned which can be used to read the content of the file; otherwise a null pointer is returned.

Parameters

const char * fileName	The absolute full path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

The IFileRead instance created. It must be freed by the C++ operator delete, if no longer be used.

Code Example

class IFileRead * file = FileSystem::OpenReadFile("/path/file.txt", log_instance);
if(file) {
....
  read operation
...
delete file;
}
                

The main function to use to open a directory corresponding to directoryName. An object of class IDirectory is returned on success and a null pointer on failure.

Parameters

const char * directoryName	The absolute full name of the directory
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

The created IDirectory instance. It must be freed by the C++ operator delete, if no longer be used.

Code Example

class IDirectory * dir = FileSystem::OpenDirectory("/dir/", log_instance);
if(dir) {
....
  perform action
...
delete dir;
}
                

The function is used to open a binary file bin. An object of class IElfBinary is returned on success and a null pointer on failure. This object can be used to get some information about an ELF (Executable and Linkable Format) binary.

Parameters

const char * bin	The absolute full name of the binary
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

The created IElfBinary instance. It must be freed by the C++ operator delete, if no longer be used.

Code Example

class IElfBinary * bin = FileSystem::OpenElfBinary(binary, log_instance);
if(bin) {
....
  perform action
...
delete bin;
}
                

Opens and reads the whole file into a buffer with a defined size. The file is closed afterwards.

Parameters

const char * filename	The absolute path of the file
char * readBuffer	The buffer in which the file is read to
size_t size	The size of the read buffer which must be big enough
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

If the read is successfull true is returned; otherwise false.

Opens a file with an absolute path and writes the whole content of the write buffer into the file. The file is closed afterwards.

Parameters

const char * filename	The absolute path of the file
char * writeBuffer	The buffer to be written to the file
size_t size	The size of the write buffer.
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

If the write is successfull true is returned; otherwise false.

Code Example

char * buffer = malloc(BIG_ENOUGH_SIZE);
FileSystem::WriteWholeFile("/path/important_file.txt", buffer, strlen(buffer), log_instance);
free(buffer);
                

Scans a file given as an absolute path, based on a set of characters specified in a format string.

Parameters

class IInstanceLog * log	The IInstanceLog instance used for loging purposes.
const char * filename	The absolute path of the file
const char * format	A string containing a set of characters that specifies how characters are extracted from the file (C string following the same specifications as in the C function scanf.)

Return value

If scanning the file is successfull, the file is closed and true is returned; otherwise false.

Code Example

long long unsigned time;
int id;
char s_string[128];
FileSystem::ScanFile(log_instance, "/path/file_to_scan", "%*32[^:]:%llu %*s %d %s", &time, &id, s_string);

Checks if a file exists.

Parameters

const char * filename	The absolute path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

If a file exists true is returned; otherwise false.

Returns the time of the last write operation performed on a file specified by an absolute path.

Parameters

const char * filename	The absolute path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success the time in seconds is retured; otherwise -1.

Returns the current size of the file.

Parameters

const char * filename	The absolute path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success the size of the file is retured; otherwise -1.

Returns the current block size of the file.

Parameters

const char * filename	The absolute path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success the block size of the file is retured; otherwise -1.

Renames a file.

Parameters

const char * oldName	The current name of the file (absolute path)
const char * newName	The new name of the file (absolute path)
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Code Example

if (FileSystem::FileExists("/path/myPbx.txt", log_instance)) {
    FileSystem::Rename("/path/myPbx.txt", "/path/myApps.txt", log_instance);
}

Removes a file.

Parameters

const char * filename	The absolute path of the file to be removed
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Creates a directory.

Parameters

const char * absolutePath	The absolute path of the directory to be created
int mode	The mode to set the file permission bits
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Code Example

//mode 0755 defined as rwxr-xr-x 
FileSystem::CreateDirectory("/home/new", 0755, log)

Removes a directory. If the directory is not empty, all included directories and files are deleted as well.

Parameters

const char * directoryPath	The absolute path of the directory to be removed
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Changes the owner and group of the directory specified by an absolute path.

Parameters

const char * path	The absolute path of the directory
const char * newOwner	The new owner of the directory
const char * newGroup	The new group of the directory
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Changes the mode of a file.

Parameters

const char * path	The absolute path of the directory to be removed
int mode	The new mode of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success true is retured; otherwise false.

Code Example

FileSystem::ChangeMode("/directory", 0744, log);

Returns the total size of the file system in bytes.

Parameters

const char * path	The absolute path of the directory to be removed
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success the size is returned in bytes; otherwise -1.

Code Example

ulong64 totalSize = FileSystem::GetFileSystemTotalSize("/mnt/sda1", log);

Returns the total used space of the file system in bytes.

Parameters

const char * path	The absolute path of the directory to be removed
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success the size is returned in bytes; otherwise -1.

Checks if a system user and group exist.

Parameters

const char * user	The system user
const char * group	The system group
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

If the user and group are available to use, true is returned; otherwise false.

Returns the system user of a file.

Parameters

const char * filepath	The absolute path of the file
class IInstanceLog * log	The IInstanceLog instance used for loging purposes.

Return value

On success, returns the system user; otherwise 0.

class IFileWrite {
public:
    ~IFileWrite() {};
    bool IsOpen();
    bool Write(const void * buffer, size_t len);
    void Flush();
    bool Close();
};

Overview

Logging

Public functions

Checks if the file is opened.

Return value

Returns true if the file is opened successfully; otherwise false.

Writes the buffer with a size len into the file.

Parameters

const void * buffer	The buffer to be written
size_t len	The length of the buffer

Return value

Returns true if the write operation was successful; otherwise false.

Flushes the stream opened for writing any unwritten data

Close the file after writing is finished. After the write operation is completed, a call to Close() should be performed explicitly.

Return value

Returns true if the the file was closed successfully; otherwise false.

Code Example

bool append = false;
class IFileWrite * file = FileSystem::OpenWriteFile("file.txt", append, log);
file->Write(buffer, strlen(buffer));
file->Close();
delete file;

class IFileRead {
public:
    virtual ~IFileRead() {};
    bool IsOpen();
    size_t Read(void * buffer, size_t len);
    bool Close();
};

Overview

Logging

Public functions

Checks if the file is opened.

Return value

Returns true if the file is opened successfully; otherwise false.

Reads the file into the buffer.

Parameters

void * buffer	The buffer to read the file into
size_t len	The length of the buffer

Return value

Returns the count of the written bytes in the buffer.

Close the file after writing is finished. After the last read operation is completed, a call to Close() should be performed explicitly.

Return value

Returns true if the the file was closed successfully; otherwise false.

class IDirectory {
public:
    ~IDirectory() {};
    bool IsOpen() const;
    class IDirectoryEntry * ReadNext();
    bool Close();
};

Overview

Logging

Public functions

Checks if the directory is opened.

Return value

Returns true if the directory is opened successfully; otherwise false.

Starts reading the first entry of the directory. This function iterates through the whole directory till end of the directory is reached or if an error occurs.

Return value

An instance of class DirectoryEntry is returned specifying whether the entry is a regular file or a directory. NULL is returned on error or if the end of directory is reached.

Closes the associated directory. A call to Close() should be done explicitly after reading is done.

Return value

Returns true if the the directory was closed successfully; otherwise false.

Code Example

class IDirectory * dir = FileSystem::OpenDirectory("/directory", log);
class IDirectoryEntry * entry;
while ((entry = dir->ReadNext())) {
    ......
    ......
    delete entry;
}
dir->Close();
delete dir;

class IDirectoryEntry {
public:
    ~IDirectoryEntry() {};
    const char * GetName() const ;
    bool IsFile() const ;
};

Overview

Logging

Public functions

Reads the name of the directory entry.

Return value

Returns the name read.

Checks if the directory entry is a regular file.

Return value

Returns true if the read directory entry is a regular file or false if the entry is a directory.

class IElfBinary {
public:
    ~IElfBinary() {};
    bool IsOpen() ;
    bool IsElfBinary() ;
    bool IsExecutable() ;
    elf_architecture_t GetArchitecture() ;
    bool Close() ;
};

Overview

Logging

Public functions

Check if the binary file is opened.

Return value

Returns true if the file is successfully opened.

Checks whether the file is a valid ELF binary. The header of the binary is read the magic number is checked.

Return value

Returns true if the binary is a valid ELF binary.

Checks whether the file is an executible ELF binary.

Return value

Returns true if the binary is executable; otherwise false.

Returns the architecture of the ELF binary. The types checked are ARM and X86_64 only.

Return value

Returns the architecture in the enum elf_architecture_t.

Closes the binary file.

Return value

Returns true if the the directory was closed successfully; otherwise false.

typedef enum {
    ELF_UNKOWN,
    ELF_ARM,
    ELF_X86_64
} elf_architecture_t;