1.[代码]safe_iconv.c

/* 在 Windows 下有许多编码是GB18030、 后缀是 cue 的文本文件，将其移到 Linux 下使用 shell 命令：

find . -type f -name "*.cue" -exec iconv -f gb18030 -t utf8 -o {} {} \;

目的是找到当前目录下所有cue文件并转码，然后替换原文件。当 iconv 转码失败时，仍然会将垃圾数据写入原文件。

而新的 safe_iconv 在转码失败时不修改原代码。safe_iconv 只适合用于小于 BUFSIZE 的文件：

find . -type f -name "*.cue" -exec safe_iconv -f gb18030 -t utf8 -o {} {} \;

*/

#include

#include

#include

#include

enum {BUFSIZE = 4096};

static iconv_t cd;

static char* fromcode;

static char* tocode;

static char* infilename;

static char* outfilename;

static char inbuf[BUFSIZE];

static char outbuf[BUFSIZE];

static FILE* fin;

static FILE* fout;

int cmdline_parsed(int argc, char*const* argv)

{

int opt;

opterr = 0;

while ( (opt=getopt(argc, argv, "f:t:o:l")) != -1 )

{

switch (opt) {

case 'f': fromcode = optarg; break;

case 't': tocode = optarg; break;

case 'o': outfilename = optarg; break;

case 'l': system("iconv -l"); return 0; //当然必须安装有 iconv。

case '?': fprintf(stderr, "error: option is \'?\'\n"); return 0;

}

}

if (! (fromcode && tocode)) {

fprintf(stderr, "error: \'fromcode\' or \'tocode\' is null.\n");

return 0;

}

infilename = argv[optind];

return 1;

}

size_t file_size(FILE* fin)

{

size_t r;

fseek(fin, 0, SEEK_END);

r = ftell(fin);

fseek(fin, 0, SEEK_SET);

return r;

}

int main(int argc, const char** argv)

{

char* pinbuf = inbuf;

char* poutbuf = outbuf;

size_t inbytesleft;

size_t outbytesleft;

size_t count;

if (! cmdline_parsed(argc, (char*const*)argv)) {

return EXIT_FAILURE;

}

cd = iconv_open(tocode, fromcode);

if (cd == (iconv_t)-1) {

fprintf(stderr, "error: f=\'%s\' t=\'%s\' i=\'%s\' o=\'%s\'\n",

fromcode, tocode, infilename, outfilename);

return EXIT_FAILURE;

}

fin = fopen(infilename, "r");

if (! fin) {

fprintf(stderr, "error: \'fopen(%s, \"r\")\'\n", infilename);

return EXIT_FAILURE;

}

inbytesleft = file_size(fin);

if (inbytesleft > BUFSIZE) {

fprintf(stderr, "error: \'%d > BUFSIZE\'\n", inbytesleft);

return EXIT_FAILURE;

}

fread(inbuf, 1, inbytesleft, fin);

outbytesleft = BUFSIZE;

count = iconv(cd, &pinbuf, &inbytesleft, &poutbuf, &outbytesleft);

if (count == (size_t)-1) {

fprintf(stderr, "error: \'iconv()\'\n");

return EXIT_FAILURE;

}

if (outfilename == NULL) {

//printf("%d %d\n", inbytesleft, outbytesleft);

printf("%s", outbuf);

}

else {

fout = fopen(outfilename, "w");

if (! fout) {

fclose(fin);

fprintf(stderr, "error: \'fopen(%s, \"w\")\'\n", outfilename);

return EXIT_FAILURE;

}

fwrite(outbuf, 1, BUFSIZE - outbytesleft, fout);

fclose(fout);

}

fclose(fin);

return EXIT_SUCCESS;

}