Files
wget2/libwget/printf.c
2024-01-07 12:41:02 +01:00

267 lines
6.5 KiB
C

/*
* Copyright (c) 2016-2024 Free Software Foundation, Inc.
*
* This file is part of libwget.
*
* Libwget is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Libwget is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libwget. If not, see <https://www.gnu.org/licenses/>.
*
*
* printf-style routines using buffer functions
*
* Changelog
* 13.01.2016 Tim Ruehsen created
*
*/
#include <config.h>
#include <wget.h>
#include "private.h"
/**
* \file
* \brief Libwget printf functions
* \defgroup libwget-printf Libwget printf functions
* @{
*
* This is a collection of printf-style functions that are used with libwget and/or Wget2 code.
* They may be useful to other developers that is why they are exported.
*/
/**
* \param[in] strp Pointer to hold the string output
* \param[in] fmt Printf-like format specifier
* \param[in] args va_list of arguments
* \return Length of the string returned via \p strp or `(size_t) -1` on error
*
* Prints arguments to allocated memory and 0-terminates it. The string is returned via the first argument.
* It has to be free()'d by the caller when it is no longer needed.
*/
size_t wget_vasprintf(char **strp, const char *fmt, va_list args)
{
wget_buffer buf;
wget_buffer_init(&buf, NULL, 128);
size_t len = wget_buffer_vprintf(&buf, fmt, args);
if (unlikely(buf.error)) {
xfree(buf.data);
return (size_t) -1;
}
if (strp) {
// shrink memory to real usage
*strp = wget_realloc(buf.data, len + 1);
} else {
// behave like C99/POSIX snprintf - just return the length
xfree(buf.data);
}
return len;
}
/**
* \param[in] strp Pointer to hold the string output
* \param[in] fmt Printf-like format specifier
* \param[in] ... List of arguments
* \return Length of the string returned via \p strp
*
* Prints arguments to allocated memory and 0-terminates it. The string is returned via the first argument.
* It has to be free()'d by the caller when it is no longer needed.
*/
size_t wget_asprintf(char **strp, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
size_t len = wget_vasprintf(strp, fmt, args);
va_end(args);
return len;
}
/**
* \param[in] fmt Printf-like format specifier
* \param[in] args va_list of arguments
* \return Pointer to 0-terminated string in memory
*
* Prints arguments to memory and returns a pointer to allocated and 0-terminated chunk of memory.
* The return value has to be free()'d by the caller when it is no longer needed.
*/
char *wget_vaprintf(const char *fmt, va_list args)
{
char *s = NULL;
wget_vasprintf(&s, fmt, args);
return s;
}
/**
* \param[in] fmt Printf-like format specifier
* \param[in] ... List of arguments
* \return Pointer to 0-terminated string in memory
*
* Prints arguments to memory and returns a pointer to allocated and 0-terminated chunk of memory.
* The return value has to be free()'d by the caller when it is no longer needed.
*/
char *wget_aprintf(const char *fmt, ...)
{
va_list args;
char *s = NULL;
va_start(args, fmt);
wget_vasprintf(&s, fmt, args);
va_end(args);
return s;
}
/**
* \param[in] fp FILE pointer
* \param[in] fmt Printf-like format specifier
* \param[in] args List of arguments
* \return Number of bytes written or -1 on error
*
* Prints arguments to stream \p fp and returns number of bytes written.
*/
size_t wget_vfprintf(FILE *fp, const char *fmt, va_list args)
{
wget_buffer buf;
char sbuf[1024];
size_t rc;
wget_buffer_init(&buf, sbuf, sizeof(sbuf));
size_t len = wget_buffer_vprintf(&buf, fmt, args);
if (unlikely(buf.error)) {
wget_buffer_deinit(&buf);
return (size_t) -1;
}
if (len > 0)
rc = fwrite(buf.data, 1, len, fp);
else
rc = 0;
wget_buffer_deinit(&buf);
return rc;
}
/**
* \param[in] fp FILE pointer
* \param[in] fmt Printf-like format specifier
* \param[in] ... List of arguments
* \return Number of bytes written or -1 on error
*
* Prints arguments to stream \p fp and returns number of bytes written.
*/
size_t wget_fprintf(FILE *fp, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
size_t rc = wget_vfprintf(fp, fmt, args);
va_end(args);
return rc;
}
/**
* \param[in] fmt Printf-like format specifier
* \param[in] ... List of arguments
* \return Number of bytes written or -1 on error
*
* Prints arguments to `stdout` and returns number of bytes written.
*/
size_t wget_printf(const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
size_t rc = wget_vfprintf(stdout, fmt, args);
va_end(args);
return rc;
}
/**
* \param[in] str Destination buffer
* \param[in] size Size of \p str
* \param[in] fmt Printf-like format specifier
* \param[in] args List of arguments
* \return Number of bytes written, or, on truncation, that would have been written
*
* Prints arguments to buffer \p str and returns number of bytes written,
* or on truncation: that would have been written.
*
* If \p str is %NULL the return value are the number of bytes that would have been written.
*/
size_t wget_vsnprintf(char *str, size_t size, const char *fmt, va_list args)
{
wget_buffer buf;
wget_buffer_init(&buf, str, size);
size_t len = wget_buffer_vprintf(&buf, fmt, args);
if (unlikely(buf.error)) {
wget_buffer_deinit(&buf);
return (size_t) -1;
}
if (str) {
if (buf.data == str) {
buf.data = NULL;
} else if (len < size) {
memcpy(str, buf.data, len + 1);
} else {
memcpy(str, buf.data, size - 1);
str[size - 1] = 0;
}
}
wget_buffer_deinit(&buf);
return len;
}
/**
* \param[in] str Destination buffer
* \param[in] size Size of \p str
* \param[in] fmt Printf-like format specifier
* \param[in] ... List of arguments
* \return Number of bytes written, or, on truncation, that would have been written
*
* Prints arguments to buffer \p str and returns number of bytes written,
* or on truncation: that would have been written.
*
* If \p str is %NULL the return value are the number of bytes that would have been written.
*/
size_t wget_snprintf(char *str, size_t size, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
size_t len = wget_vsnprintf(str, size, fmt, args);
va_end(args);
return len;
}
/**@}*/