libiconv交叉编译提示arm-none-linux-gnueabi-gcc


title: libiconv交叉编译提示arm-none-linux-gnueabi-gcc

date: 2019/3/6 17:45:48

toc: true

libiconv交叉编译提示arm-none-linux-gnueabi-gcc

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iconv.h> int main(int argc, char **argv)
{
/* 目的编码, TRANSLIT:遇到无法转换的字符就找相近字符替换
* IGNORE :遇到无法转换字符跳过*/
//char *encTo = "UNICODE//TRANSLIT";
int i;
char *encTo = "UTF-8";
/* 源编码 */
char *encFrom = "GBK"; iconv_t cd = iconv_open (encTo, encFrom);
if (cd == (iconv_t)-1)
{
perror ("iconv_open");
return -1;
} /* 需要转换的字符串 */
// GBK D6D0 B9FA
// unicode 4E2D 56FD
// UTF-8 E4B8AD E59BBD
char inbuf[1024] = {0xD6,0xD0,0xB9,0xFA};
size_t srclen = strlen (inbuf);
/* 打印需要转换的字符串的长度 */
printf("srclen=%ld\n", srclen); i=0;
printf("input= ");
while (inbuf[i]) {
printf("%x ",(unsigned char)inbuf[i]);
i++;
}
printf("\n"); /* 存放转换后的字符串 */
size_t outlen = 1024;
char outbuf[outlen];
memset (outbuf, 0, outlen); /* 由于iconv()函数会修改指针,所以要保存源指针 */
char *srcstart = inbuf;
char *tempoutbuf = outbuf; /* 进行转换
*@param cd iconv_open()产生的句柄
*@param srcstart 需要转换的字符串
*@param srclen 存放还有多少字符没有转换
*@param tempoutbuf 存放转换后的字符串
*@param outlen 存放转换后,tempoutbuf剩余的空间
*
* */
size_t ret = iconv (cd, &srcstart, &srclen, &tempoutbuf, &outlen);
if (ret == -1)
{
perror ("iconv err\n");
return -1;
}
printf ("ret is %ld\n",ret);
printf ("outlen is %ld\n",1024-outlen); printf("out is \n");
for (i=0;i<10;i++) {
printf("%x ",(unsigned char)outbuf[i]);
}
printf("\n"); iconv_close (cd);
return 0;
}

最终显示结果

/mnt/repo/test/libiconv-1.15 #  ../arm
srclen=4
input= d6 d0 b9 fa
ret is 0
outlen is 6
out is
e4 b8 ad e5 9b bd 0 0 0 0

移植到ARM

1.14版本直接成功,1.15(最新)失败了,折腾了好久

先下载了最先的libiconv-1.15.tar.gz版本,解压配置

./configure --prefix=$PWD/out --host=arm-linux
make
make install

然后提示

arm-none-linux-gnueabi-gcc: 0": No such file or directory
<command-line>: warning: missing terminating " character
Makefile:50: recipe for target 'preloadable_libiconv.so' failed
make[1]: *** [preloadable_libiconv.so] Error 1
make[1]: Leaving directory '/home/book/stu/repo/test/libiconv-1.15/preload'
Makefile:33: recipe for target 'all' failed
make: *** [all] Error 2

查看下自己的编译工具,是有这个的arm-none-linux-gnueabi-gcc

book@100ask:~$ echo $PATH
/home/book/bin:/home/book/.local/bin:/opt/slickedit-pro2017/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/local/arm/4.3.2/bin/:/snap/bin
book@100ask:~$ book@100ask:~$ cd /usr/local/arm/4.3.2/bin/
book@100ask:/usr/local/arm/4.3.2/bin$ ls
arm-linux-addr2line arm-linux-gcc arm-linux-nm arm-linux-strings arm-none-linux-gnueabi-cpp arm-none-linux-gnueabi-gprof arm-none-linux-gnueabi-size
arm-linux-ar arm-linux-gcc-4.3.2 arm-linux-objcopy arm-linux-strip arm-none-linux-gnueabi-g++ arm-none-linux-gnueabi-ld arm-none-linux-gnueabi-sprite
arm-linux-as arm-linux-gcov arm-linux-objdump arm-none-linux-gnueabi-addr2line arm-none-linux-gnueabi-gcc arm-none-linux-gnueabi-nm arm-none-linux-gnueabi-strings
arm-linux-c++ arm-linux-gdb arm-linux-ranlib arm-none-linux-gnueabi-ar arm-none-linux-gnueabi-gcc-4.3.2 arm-none-linux-gnueabi-objcopy arm-none-linux-gnueabi-strip
arm-linux-c++filt arm-linux-gdbtui arm-linux-readelf arm-none-linux-gnueabi-as arm-none-linux-gnueabi-gcov arm-none-linux-gnueabi-objdump
arm-linux-cpp arm-linux-gprof arm-linux-size arm-none-linux-gnueabi-c++ arm-none-linux-gnueabi-gdb arm-none-linux-gnueabi-ranlib
arm-linux-g++ arm-linux-ld arm-linux-sprite arm-none-linux-gnueabi-c++filt arm-none-linux-gnueabi-gdbtui arm-none-linux-gnueabi-readelf book@100ask:/usr/local/arm/4.3.2/bin$ ls arm-none-linux-gnueabi-gcc
arm-none-linux-gnueabi-gcc

网上搜素一圈都说安装一个库,然而都安装补上了

sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0

后来找到这里,指定CC然后make就好了

./configure --prefix=$PWD/out --host=arm-linux CC=/usr/local/arm/4.3.2/bin/arm-linux-gcc

总结

./configure --prefix=$PWD/out --host=arm-linux CC=/usr/local/arm/4.3.2/bin/arm-linux-gcc
make
make install 然后复制到单板的lib下
cp out/lib/preloadable_libiconv.so /lib/
配置动态库
export LD_PRELOAD=/lib/preloadable_libiconv.so
# 卸载这个动态库,如果要删除so,需要先卸载
unset LD_PRELOAD

LD_PRELOAD 使用

  1. 定义与目标函数完全一样的函数,包括名称、变量及类型、返回值及类型等
  2. 将包含替换函数的源码编译为动态链接库
  3. 通过命令 export LD_PRELOAD="库文件路径",设置要优先替换动态链接库
  4. 如果找不替换库,可以通过 export LD_LIBRARY_PATH=库文件所在目录路径,设置系统查找库的目录
  5. 替换结束,要还原函数调用关系,用命令unset LD_PRELOAD 解除
  6. 想查询依赖关系,可以用ldd 程序名称

LD_PRELOAD,是个环境变量,用于动态库的加载,动态库加载的优先级最高,一般情况下,其加载顺序为LD_PRELOAD>LD_LIBRARY_PATH>/etc/ld.so.cache>/lib>/usr/lib。

参考文档

arm移植libiconv(字符编码转换) https://blog.csdn.net/dyzhen/article/details/50864419

LD_PRELOAD的偷梁换柱之能 https://www.cnblogs.com/net66/p/5609026.html

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