GNU C库提供了iconv的实现 – 我该如何使用它？
简单程序：
#include <iconv.h>
int main( int argc, char **argv ) {
iconv_t cd = iconv_open( "UTF-8", "ISO-8859-1" );
iconv_close( cd );
return 0;
}
编译和链接：
$gcc -Wall iconv.c -o iconv
/tmp/ccKAfXNg.o: In function `main':
iconv.c:(.text+0x19): undefined reference to `libiconv_open'
iconv.c:(.text+0x29): undefined reference to `libiconv_close'
collect2: ld returned 1 exit status
列出符号以显示它们存在！
$nm -D /lib/libc-2.12.1.so | grep iconv
00017920 T iconv
00017ae0 T iconv_close
00017720 T iconv_open
如果我将GNU libiconv库安装到/usr/local并与-liconv链接,则可以正常工作.如何链接iconv的glibc实现？
编辑：根据评论要求提供更多信息：
列出/ usr中的所有iconv.h文件(1匹配)
$find /usr/ | grep "iconv\.h"
/usr/include/iconv.h
重新安装libc6-dev以确保安装了正确的标头.
$dpkg -S /usr/include/iconv.h
libc6-dev: /usr/include/iconv.h
$apt-get install --reinstall libc6-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0B/4,910kB of archives.
After this operation, 0B of additional disk space will be used.
(Reading database ... 143458 files and directories currently installed.)
Preparing to replace libc6-dev 2.12.1-0ubuntu10.1 (using .../libc6-dev_2.12.1-0ubuntu10.1_i386.deb) ...
Unpacking replacement libc6-dev ...
Setting up libc6-dev (2.12.1-0ubuntu10.1) ...
使用建议的预处理器选项再次编译和链接：
$gcc -Wall -DLIBICONV_PLUG iconv.c -o iconv
/tmp/ccKAfXNg.o: In function `main':
iconv.c:(.text+0x19): undefined reference to `libiconv_open'
iconv.c:(.text+0x29): undefined reference to `libiconv_close'
collect2: ld returned 1 exit status
gcc -H的输出：
$gcc -H iconv.c
. /usr/include/iconv.h
.. /usr/include/features.h
... /usr/include/bits/predefs.h
... /usr/include/sys/cdefs.h
.... /usr/include/bits/wordsize.h
... /usr/include/gnu/stubs.h
.... /usr/include/bits/wordsize.h
.... /usr/include/gnu/stubs-32.h
.. /usr/lib/gcc/i686-linux-gnu/4.4.5/include/stddef.h
Multiple include guards may be useful for:
/usr/include/bits/predefs.h
/usr/include/gnu/stubs-32.h
/usr/include/gnu/stubs.h
/usr/lib/gcc/i686-linux-gnu/4.4.5/include/stddef.h
pastbin copy of /usr/include/iconv.h
修复：重启修复了问题.我怀疑libiconv的缓存副本导致了冲突,即使它已从磁盘中删除.
解决方法:
你的程序看起来很好,在我的系统上编译得很好(Mandriva Linux 2010.1).
不过,我发现编译日志中的libiconv_ *引用令人担忧.您确定包含的iconv.h版本来自glibc而不是来自单独的libiconv实现,例如GNU libiconv吗？听起来好像它为所有iconv函数添加了一个lib前缀,以避免与系统附带的C库的iconv实现发生符号冲突.
必须明确链接到libiconv指向一个单独的iconv实现 – glibc不需要它.
编辑：
为了记录,我刚刚验证了使用来自libiconv的iconv.h头文件而没有明确地链接它将产生你所看到的结果 – 它通过在其名称中添加一个lib前缀来重命名所有iconv函数.