libyang  2.1.4
libyang is YANG data modelling language parser and toolkit written (and providing API) in C.
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
out.h File Reference

libyang output structures and functions More...

#include <stdio.h>
#include <sys/types.h>
#include "log.h"

Go to the source code of this file.

Macros

#define LY_PRINT_SHRINK   0x02
 Common value for data as well as schema printers to avoid formatting indentations and new lines. More...
 

Typedefs

typedef enum LY_OUT_TYPE LY_OUT_TYPE
 Types of the printer's output. More...
 
typedef ssize_t(* ly_write_clb )(void *user_data, const void *buf, size_t count)
 Generic write callback for data printed by libyang. More...
 

Enumerations

enum  LY_OUT_TYPE {
  LY_OUT_ERROR = -1, LY_OUT_FD, LY_OUT_FDSTREAM, LY_OUT_FILE,
  LY_OUT_FILEPATH, LY_OUT_MEMORY, LY_OUT_CALLBACK
}
 Types of the printer's output. More...
 

Functions

LIBYANG_API_DECL ly_write_clb ly_out_clb (struct ly_out *out, ly_write_clb writeclb)
 Get or reset callback function associated with a callback printer handler. More...
 
LIBYANG_API_DECL void * ly_out_clb_arg (struct ly_out *out, void *arg)
 Get or reset callback function's argument associated with a callback printer handler. More...
 
LIBYANG_API_DECL int ly_out_fd (struct ly_out *out, int fd)
 Get or reset file descriptor printer handler. More...
 
LIBYANG_API_DECL FILE * ly_out_file (struct ly_out *out, FILE *f)
 Get or reset file stream printer handler. More...
 
LIBYANG_API_DECL const char * ly_out_filepath (struct ly_out *out, const char *filepath)
 Get or change the filepath of the file where the printer prints the data. More...
 
LIBYANG_API_DECL void ly_out_free (struct ly_out *out, void(*clb_arg_destructor)(void *arg), ly_bool destroy)
 Free the printer handler. More...
 
LIBYANG_API_DECL char * ly_out_memory (struct ly_out *out, char **strp, size_t size)
 Get or change memory where the data are dumped. More...
 
LIBYANG_API_DECL LY_ERR ly_out_new_clb (ly_write_clb writeclb, void *user_data, struct ly_out **out)
 Create printer handler using callback printer function. More...
 
LIBYANG_API_DECL LY_ERR ly_out_new_fd (int fd, struct ly_out **out)
 Create printer handler using file descriptor. More...
 
LIBYANG_API_DECL LY_ERR ly_out_new_file (FILE *f, struct ly_out **out)
 Create printer handler using file stream. More...
 
LIBYANG_API_DECL LY_ERR ly_out_new_filepath (const char *filepath, struct ly_out **out)
 Create printer handler file of the given filename. More...
 
LIBYANG_API_DECL LY_ERR ly_out_new_memory (char **strp, size_t size, struct ly_out **out)
 Create printer handler using memory to dump data. More...
 
LIBYANG_API_DECL size_t ly_out_printed (const struct ly_out *out)
 Get the number of printed bytes by the last function. More...
 
LIBYANG_API_DECL LY_ERR ly_out_reset (struct ly_out *out)
 Reset the output medium to write from its beginning, so the following printer function will rewrite the current data instead of appending. More...
 
LIBYANG_API_DECL LY_OUT_TYPE ly_out_type (const struct ly_out *out)
 Get output type of the printer handler. More...
 
LIBYANG_API_DECL LY_ERR ly_print (struct ly_out *out, const char *format,...)
 Generic printer of the given format string into the specified output. More...
 
LIBYANG_API_DECL void ly_print_flush (struct ly_out *out)
 Flush the output from any internal buffers and clean any auxiliary data. More...
 
LIBYANG_API_DECL LY_ERR ly_write (struct ly_out *out, const char *buf, size_t len)
 Generic printer of the given string buffer into the specified output. More...
 

Detailed Description

libyang output structures and functions

Author
Radek Krejci rkrej.nosp@m.ci@c.nosp@m.esnet.nosp@m..cz Copyright (c) 2015-2020 CESNET, z.s.p.o.

This source code is licensed under BSD 3-Clause License (the "License"). You may not use this file except in compliance with the License. You may obtain a copy of the License at

https://opensource.org/licenses/BSD-3-Clause

Definition in file out.h.

Macro Definition Documentation

#define LY_PRINT_SHRINK   0x02

Common value for data as well as schema printers to avoid formatting indentations and new lines.

Definition at line 89 of file out.h.

Typedef Documentation

typedef enum LY_OUT_TYPE LY_OUT_TYPE

Types of the printer's output.

typedef ssize_t(* ly_write_clb)(void *user_data, const void *buf, size_t count)

Generic write callback for data printed by libyang.

Parameters
[in]user_dataOptional caller-specific argument.
[in]bufData to write.
[in]countNumber of bytes to write.
Returns
Number of printed bytes.
Negative value in case of error.

Definition at line 136 of file out.h.

Enumeration Type Documentation

Types of the printer's output.

Enumerator
LY_OUT_ERROR 

error value to indicate failure of the functions returning LY_OUT_TYPE

LY_OUT_FD 

file descriptor printer

LY_OUT_FDSTREAM 

internal replacement for LY_OUT_FD in case vdprintf() is not available

LY_OUT_FILE 

FILE stream printer

LY_OUT_FILEPATH 

filepath printer

LY_OUT_MEMORY 

memory printer

LY_OUT_CALLBACK 

callback printer

Definition at line 94 of file out.h.

Function Documentation

LIBYANG_API_DECL ly_write_clb ly_out_clb ( struct ly_out out,
ly_write_clb  writeclb 
)

Get or reset callback function associated with a callback printer handler.

Parameters
[in]outPrinter handler.
[in]writeclbOptional argument providing a new printer callback function for the handler. If NULL, only the current printer callback is returned.
Returns
Previous printer callback.
LIBYANG_API_DECL void* ly_out_clb_arg ( struct ly_out out,
void *  arg 
)

Get or reset callback function's argument associated with a callback printer handler.

Parameters
[in]outPrinter handler.
[in]argcaller-specific argument to be passed to the callback function associated with the printer handler. If NULL, only the current file descriptor value is returned.
Returns
The previous callback argument.
LIBYANG_API_DECL int ly_out_fd ( struct ly_out out,
int  fd 
)

Get or reset file descriptor printer handler.

Parameters
[in]outPrinter handler.
[in]fdOptional value of a new file descriptor for the handler. If -1, only the current file descriptor value is returned.
Returns
Previous value of the file descriptor. Note that caller is responsible for closing the returned file descriptor in case of setting new descriptor fd.
-1 in case of error when setting up the new file descriptor.
LIBYANG_API_DECL FILE* ly_out_file ( struct ly_out out,
FILE *  f 
)

Get or reset file stream printer handler.

Parameters
[in]outPrinter handler.
[in]fOptional new file stream for the handler. If NULL, only the current file stream is returned.
Returns
Previous file stream of the handler. Note that caller is responsible for closing the returned stream in case of setting new stream f.
LIBYANG_API_DECL const char* ly_out_filepath ( struct ly_out out,
const char *  filepath 
)

Get or change the filepath of the file where the printer prints the data.

Note that in case of changing the filepath, the current file is closed and a new one is created/opened instead of renaming the previous file. Also note that the previous filepath string is returned only in case of not changing it's value.

Parameters
[in]outPrinter handler.
[in]filepathOptional new filepath for the handler. If and only if NULL, the current filepath string is returned.
Returns
Previous filepath string in case the filepath argument is NULL.
NULL if changing filepath succeeds and ((void *)-1) otherwise.
LIBYANG_API_DECL void ly_out_free ( struct ly_out out,
void(*)(void *arg)  clb_arg_destructor,
ly_bool  destroy 
)

Free the printer handler.

Parameters
[in]outPrinter handler to free.
[in]clb_arg_destructorFreeing function for printer callback (LY_OUT_CALLBACK) argument.
[in]destroyFlag to free allocated buffer (for LY_OUT_MEMORY) or to close stream/file descriptor (for LY_OUT_FD, LY_OUT_FDSTREAM and LY_OUT_FILE)
LIBYANG_API_DECL char* ly_out_memory ( struct ly_out out,
char **  strp,
size_t  size 
)

Get or change memory where the data are dumped.

Parameters
[in]outPrinter handler.
[in]strpOptional new string pointer to store the resulting data, same rules as in ly_out_new_memory() are applied.
[in]sizeSize of the buffer provided via strp. In case it is 0, the buffer for the printed data is newly allocated even if strp points to a pointer to an existing buffer. In case the strp is NULL, this parameter is ignored.
Returns
Previous dumped data. Note that the caller is responsible to free the data in case of changing string pointer strp.
LIBYANG_API_DECL LY_ERR ly_out_new_clb ( ly_write_clb  writeclb,
void *  user_data,
struct ly_out **  out 
)

Create printer handler using callback printer function.

Parameters
[in]writeclbPointer to the printer callback function writing the data (see write(2)).
[in]user_dataOptional caller-specific argument to be passed to the writeclb callback.
[out]outCreated printer handler supposed to be passed to different ly*_print() functions.
Returns
LY_SUCCESS in case of success
LY_EMEM in case allocating the out handler fails.
LIBYANG_API_DECL LY_ERR ly_out_new_fd ( int  fd,
struct ly_out **  out 
)

Create printer handler using file descriptor.

Parameters
[in]fdFile descriptor to use.
[out]outCreated printer handler supposed to be passed to different ly*_print() functions.
Returns
LY_SUCCESS in case of success
LY_ERR value in case of failure.
LIBYANG_API_DECL LY_ERR ly_out_new_file ( FILE *  f,
struct ly_out **  out 
)

Create printer handler using file stream.

Parameters
[in]fFile stream to use.
[out]outCreated printer handler supposed to be passed to different ly*_print() functions.
Returns
LY_SUCCESS in case of success
LY_ERR value in case of failure.
LIBYANG_API_DECL LY_ERR ly_out_new_filepath ( const char *  filepath,
struct ly_out **  out 
)

Create printer handler file of the given filename.

Parameters
[in]filepathPath of the file where to write data.
[out]outCreated printer handler supposed to be passed to different ly*_print() functions.
Returns
NULL in case of error.
Created printer handler supposed to be passed to different ly*_print_*() functions.
LIBYANG_API_DECL LY_ERR ly_out_new_memory ( char **  strp,
size_t  size,
struct ly_out **  out 
)

Create printer handler using memory to dump data.

Parameters
[in]strpPointer to store the resulting data. If it points to a pointer to an allocated buffer and size of the buffer is set, the buffer is used (and extended if needed) to store the printed data.
[in]sizeSize of the buffer provided via strp. In case it is 0, the buffer for the printed data is newly allocated even if strp points to a pointer to an existing buffer.
[out]outCreated printer handler supposed to be passed to different ly*_print() functions.
Returns
LY_SUCCESS in case of success
LY_ERR value in case of failure.
LIBYANG_API_DECL size_t ly_out_printed ( const struct ly_out out)

Get the number of printed bytes by the last function.

Parameters
[in]outOut structure used.
Returns
Number of printed bytes.
LIBYANG_API_DECL LY_ERR ly_out_reset ( struct ly_out out)

Reset the output medium to write from its beginning, so the following printer function will rewrite the current data instead of appending.

Note that in case the underlying output is not seekable (stream referring a pipe/FIFO/socket or the callback output type), nothing actually happens despite the function succeeds. Also note that the medium is not returned to the state it was when the handler was created. For example, file is seeked into the offset zero and truncated, the content from the time it was opened with ly_out_new_file() is not restored.

Parameters
[in]outPrinter handler.
Returns
LY_SUCCESS in case of success
LY_ESYS in case of failure
LIBYANG_API_DECL LY_OUT_TYPE ly_out_type ( const struct ly_out out)

Get output type of the printer handler.

Parameters
[in]outPrinter handler.
Returns
Type of the printer's output.
LIBYANG_API_DECL LY_ERR ly_print ( struct ly_out out,
const char *  format,
  ... 
)

Generic printer of the given format string into the specified output.

Alternatively, ly_write() can be used.

Parameters
[in]outOutput specification.
[in]formatFormat string to be printed.
Returns
LY_ERR value, get number of the printed bytes using ly_out_printed.
LIBYANG_API_DECL void ly_print_flush ( struct ly_out out)

Flush the output from any internal buffers and clean any auxiliary data.

Parameters
[in]outOutput specification.
LIBYANG_API_DECL LY_ERR ly_write ( struct ly_out out,
const char *  buf,
size_t  len 
)

Generic printer of the given string buffer into the specified output.

Alternatively, ly_print() can be used.

Parameters
[in]outOutput specification.
[in]bufMemory buffer with the data to print.
[in]lenLength of the data to print in the buf.
Returns
LY_ERR value, get number of the printed bytes using ly_out_printed.