qfile.c File Reference

File handling APIs. More...

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Macros
#define	MAX_EXTENSION_LENGTH   (8)

Functions
bool	qfile_lock (int fd)
	Lock file.
bool	qfile_unlock (int fd)
	Unlock file which is locked by qfile_lock()
bool	qfile_exist (const char *filepath)
	Check file existence.
void *	qfile_load (const char *filepath, size_t *nbytes)
	Load file into memory.
void *	qfile_read (FILE *fp, size_t *nbytes)
	Read data from a file stream.
ssize_t	qfile_save (const char *filepath, const void *buf, size_t size, bool append)
	Save data into file.
bool	qfile_mkdir (const char *dirpath, mode_t mode, bool recursive)
	Attempts to create a directory recursively.
bool	qfile_check_path (const char *path)
	Check path string contains invalid characters.
char *	qfile_get_name (const char *filepath)
	Get filename from filepath.
char *	qfile_get_dir (const char *filepath)
	Get directory suffix from filepath.
char *	qfile_get_ext (const char *filepath)
	Get extension from filepath.
off_t	qfile_get_size (const char *filepath)
	Get file size.
char *	qfile_correct_path (char *path)
	Correct path string.
char *	qfile_abspath (char *buf, size_t bufsize, const char *path)
	Make full absolute system path string.

Detailed Description

File handling APIs.

Definition in file qfile.c.

Function Documentation

qfile_lock()

bool qfile_lock

(

int

fd

)

Lock file.

Parameters

fd	file descriptor

Returns

true if successful, otherwise returns false.

// for file descriptor
int fd = open(...);
if(qfile_lock(fd) == true) {
  (...atomic file access...)
  qfile_unlock(fd);
}
 
// for FILE stream object
FILE *fp = fopen(...);
int fd = fileno(fp);
if(qfile_lock(fd) == true) {
  (...atomic file access...)
  qfile_unlock(fd);
}

Definition at line 74 of file qfile.c.

qfile_unlock()

bool qfile_unlock

(

int

fd

)

Unlock file which is locked by qfile_lock()

Parameters

fd	file descriptor

Returns

true if successful, otherwise returns false.

Definition at line 98 of file qfile.c.

qfile_exist()

bool qfile_exist

(

const char *

filepath

)

Check file existence.

Parameters

filepath

file or directory path

Returns

true if exists, otherwise returns false.

Definition at line 122 of file qfile.c.

qfile_load()

void * qfile_load	(	const char *	filepath,
		size_t *	nbytes
	)

Load file into memory.

Parameters

filepath	file path
nbytes	has two purpost, one is to set how many bytes are readed. the other is actual the number loaded bytes will be stored. nbytes must be point 0 or NULL to read entire file.

Returns

allocated memory pointer if successful, otherwise returns NULL.

// loading text file
char *text = (char *)qfile_load("/tmp/text.txt", NULL);
 
// loading binary file
int binlen = 0;
char *bin = (char *)qfile_load("/tmp/binary.bin", &binlen);
 
// loading partial
int binlen = 10;
char *bin = (char *)qfile_load("/tmp/binary.bin", &binlen);

Note

This method actually allocates memory more than 1 bytes than filesize then append NULL character at the end. For example, when the file size is 10 bytes long, 10+1 bytes will allocated and the last byte is always NULL character. So you can load text file and use without appending NULL character. By the way, the actual file size 10 will be returned at nbytes variable.

Definition at line 159 of file qfile.c.

qfile_read()

void * qfile_read	(	FILE *	fp,
		size_t *	nbytes
	)

Read data from a file stream.

Parameters

fp	FILE pointer
nbytes	has two purpose, one is to set bytes to read. the other is to return actual number of bytes loaded. 0 or NULL can be set to read file until the end.

Returns

allocated memory pointer if successful, otherwise returns NULL.

int binlen = 0;
char *bin = (char *)qfile_read(fp, &binlen);

Note

This method append NULL character at the end of stream. but nbytes only counts actual readed bytes.

Definition at line 214 of file qfile.c.

qfile_save()

ssize_t qfile_save	(	const char *	filepath,
		const void *	buf,
		size_t	size,
		bool	append
	)

Save data into file.

Parameters

filepath	file path
buf	data
size	the number of bytes to save
append	false for new(if exists truncate), true for appending

Returns

the number of bytes written if successful, otherwise returns -1.

// save text
char *text = "hello";
qfile_save("/tmp/text.txt", (void*)text, strlen(text), false);
 
// save binary
int integer1 = 75;
qfile_save("/tmp/integer.bin, (void*)&integer, sizeof(int));

Definition at line 283 of file qfile.c.

qfile_mkdir()

bool qfile_mkdir	(	const char *	dirpath,
		mode_t	mode,
		bool	recursive
	)

Attempts to create a directory recursively.

Parameters

dirpath	directory path
mode	permissions to use
recursive	whether or not to create parent directories automatically

Returns

true if successful, otherwise returns false.

Definition at line 312 of file qfile.c.

qfile_check_path()

bool qfile_check_path

(

const char *

path

)

Check path string contains invalid characters.

Parameters

path	path string

Returns

true if ok, otherwise returns false.

Definition at line 337 of file qfile.c.

qfile_get_name()

char * qfile_get_name

(

const char *

filepath

)

Get filename from filepath.

Parameters

filepath

file or directory path

Returns

malloced filename string

Definition at line 356 of file qfile.c.

qfile_get_dir()

char * qfile_get_dir

(

const char *

filepath

)

Get directory suffix from filepath.

Parameters

filepath

file or directory path

Returns

malloced filepath string

Definition at line 371 of file qfile.c.

qfile_get_ext()

char * qfile_get_ext

(

const char *

filepath

)

Get extension from filepath.

Parameters

filepath

file or directory path

Returns

malloced extension string which is converted to lower case.

Definition at line 386 of file qfile.c.

qfile_get_size()

off_t qfile_get_size

(

const char *

filepath

)

Get file size.

Parameters

filepath

file or directory path

Returns

the file size if exists, otherwise returns -1.

Definition at line 410 of file qfile.c.

qfile_correct_path()

char * qfile_correct_path

(

char *

path

)

Correct path string.

Parameters

path	path string

Returns

path string pointer

Note

This modify path argument itself.

"/hello//my/../world" => "/hello/world"
"././././hello/./world" => "./hello/world"
"/../hello//world" => "/hello/world"
"/../hello//world/" => "/hello/world"

Definition at line 434 of file qfile.c.

qfile_abspath()

char * qfile_abspath	(	char *	buf,
		size_t	bufsize,
		const char *	path
	)

Make full absolute system path string.

Parameters

buf	buffer string pointer
bufsize	buffer size
path	path string

Returns

buffer pointer if successful, otherwise returns NULL.

char buf[PATH_MAX];
chdir("/usr/local");
qfile_abspath(buf, sizeof(buf), ".");    // returns "/usr/local"
qfile_abspath(buf, sizeof(buf), "..");   // returns "/usr"
qfile_abspath(buf, sizeof(buf), "etc");  // returns "/usr/local/etc"
qfile_abspath(buf, sizeof(buf), "/etc"); // returns "/etc"
qfile_abspath(buf, sizeof(buf), "/etc/"); // returns "/etc/"

Definition at line 530 of file qfile.c.