Linux下获取当前进程的执行文件的绝对路径和所在目录(通过/proc/self/exe链接)

浏览数：32 / 时间：2015年06月20日

#include <stdio.h>
#include <string.h> 　　//strrchr(), strncpy()
#include <stdlib.h>   　 //realloc()
#include <unistd.h>   //readlink()

#define MAXBUFSIZE 1024

//通过链接文件名获取被目标文件绝对路径
//为了防止buffer不够大，包装一下readlink()
char* getFilePathByLink(const char *filename)
{
int size = 100;
char *buffer = NULL;

while(1)
    {
      buffer = (char *) realloc(buffer, size);
      //readlink()返回的路径名并没有以‘\0‘结尾
      int nchars = readlink(filename, buffer, size - 1);
      if (nchars < 0)
        {
          free(buffer);
          return NULL;
        }
      if (nchars <= size - 1) {
   buffer[nchars] = ‘\0‘;       //让路径名以‘\0‘结尾
        return buffer;
      }
      size *= 2;   //buffer空间不足，扩大为2倍
    }
}

//通过链接文件名获取被目标文件所在目录
char* getFileDirByLink(const char *linkfile)
{
    char* pathbuf = NULL;
    pathbuf = getFilePathByLink(linkfile);
    if (NULL == pathbuf) {
          printf("getFilePathByLink() Failed!\n");
          return(NULL);
    }

   char* last_slash = NULL;
    //找到最后一个‘/‘,last_slash保存其地址
   last_slash = strrchr(pathbuf, ‘/‘);
   //如果是空，则未找到‘/‘
   if (last_slash == NULL) {
        printf("can not find ‘/‘!\n");
          return(NULL);
    }

   int dir_len = 0;
   char* dir = NULL;
   dir_len = last_slash - pathbuf + 1;       //包括末尾的‘/‘
   dir = (char*) malloc(dir_len + 1);

   strncpy(dir, pathbuf, dir_len);
   dir[dir_len] = ‘\0‘;

   return dir;
}

int main( int argc, char * argv[] )
{
    char* myself_exec = NULL;
    myself_exec = getFilePathByLink("/proc/self/exe");
    if (NULL == myself_exec) {
          printf("getFilePathByLink() Failed!\n");
    } else {
       printf("I‘m the process, my executable file: %s\n", myself_exec);
    }

    char* myself_exec_dir = NULL;
    myself_exec_dir = getFileDirByLink("/proc/self/exe");
    printf("I‘m the process, my executable file in: %s\n", myself_exec_dir);

    free(myself_exec);
    free(myself_exec_dir);
    return(EXIT_SUCCESS);
}