libxml2中文支持

  LibXML2自身已經支持了中文編碼，只是他的所有api處理的數據都是UTF-8類型的，所以只要在讀入和寫入數據時進行相應裝換即可！

代碼1是使用Linux下C API進行編碼轉換;

代碼2因爲libxml2已經融合了iconv，使用了libxml2的函數來進行編碼轉換。

/*
compile: gcc -l/usr/include/libxml2 -lxml2 iconv.c
input:
    test.xml
        <?xml version="1.0" encoding="gb2312"?>
        <parent>測試</parent>
output:
    測試
1) iconv
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <arpa/inet.h>
#include <iconv.h>

char *Convert(char *encFrom, char *encTo, const char *in)
{
    static char bufin[1024], bufout[1024], *sin, *sout;
    int mode, lenin, lenout, ret, nline;
    iconv_t c_pt;

    if ((c_pt = iconv_open(encTo, encFrom)) == (iconv_t)-1) {
        printf("iconv_open false: %s ==> %s\n", encFrom, encTo);
        return NULL;
    }
    iconv(c_pt, NULL, NULL, NULL, NULL);

    lenin = strlen(in) + 1;
    lenout = 1024;
    sin = (char *)in;
    sout = bufout;
    ret = iconv(c_pt, &sin, (size_t *)&lenin, &sout, (size_t *)&lenout);

    if (ret == -1) {
        return NULL;
    }

    iconv_close(c_pt);
    return bufout;
}

int main(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr cur = NULL;

    doc = xmlParseFile("test.xml");
    cur = xmlDocGetRootElement(doc);
    printf("%s\n", (char *)xmlNodeGetContent(cur));
    //printf(%s\n", Convert("utf-8", "gb2312", (char*)xmlNodeGetContent(cur)));
}

2) xmlFindCharEncodingHandler

使用數據類型: xmlCharEncodingHandlerPtr

/*******************************************
* compile: gcc -l/usr/include/libxml2/ -lxml2 convert.c
* usage: convert utf-8 string or null
* input: /convert 測試
* output:
    [wuqifu@localhost test]$ ./convert 測試
    ISO-8859-1: 
        虜芒脢脭
<?xml version="1.0" encoding="ISO-8859-1"?>
<root>測試</root>
**************************************/

#include <libxml/encoding.h>
/**
 * function name: ConvertInput
 * input:
    @in: string in a given encoding
    @encoding: the encoding used
* description: Converts @in into UTF-8 for processing with libxml2 APIs
* return: returns the converted UTF-8 string, or NULL in case of error.
**/
unsigned char *ConvertInput(const char *in, const char *encoding)
{
    unsigned char *out;
    int ret;
    int size;
    int out_size;
    int temp;
    xmlCharEncodingHandlerPtr handler;

    if (in == 0) return 0;

    handler = xmlFindCharEncodingHandler(encoding);

    if (!handler) {
        printf("ConvertInput: no encoding handler found for '%s'\n",
            encoding ? encoding : "");
        return 0;
    }

    size = (int) strlen(in) + 1;
    out_size = size * 2 - 1;
    out = (unsigned char *)xmlMalloc((size_t) out_size);

    if (out != 0) {
        temp = size - 1;
        ret = handler->input(out, &out_size, (const unsigned char *)in, &temp);
        if ((ret < 0) || (temp - size + 1)) {
            if (ret < 0) {
                printf("ConvertInput: conversion wasn't successful.\n");
            } else {
                printf("ConvertInput: conversion wasn't successful. converted: %i octets.\n", temp);
            }
            xmlFree(out);
            out = 0;
        } else {
            out = (unsigned char *)xmlRealloc(out, out_size + 1);
            out[out_size] = 0; /* null terminating out */
        }
    } else {
        printf("ConvertInput: no mem\n");
    }

    return out;
}

int main(int argc, char **argv)
{
    unsigned char *content, *out;
    xmlDocPtr doc;
    xmlNodePtr rootnode;
    char *encoding = "ISO-8859-1"; //utf-8, ISO-8859-1
    if (argc <= 1) {
        printf("Usage: %s content\n", argv[0]);
        return (0);
    }
    content = argv[1];

    out = ConvertInput(content, encoding);
    printf("%s:%s\n", encoding, out);
    doc = xmlNewDoc("1.0");
    rootnode = xmlNewDocNode(doc, NULL, (const xmlChar*)"root", out);
    xmlDocSetRootElement(doc, rootnode);
    xmlSaveFormatFileEnc("=", doc, encoding, 1);
    return 1;
}