如何实现readlink查找路径
如何实现readlink查找路径
提问于 2011-04-03 04:29:30
使用readlink函数作为How do I find the location of the executable in C?的解决方案，如何将路径放入字符数组？另外，变量buf和bufsize代表什么，我如何初始化它们？
编辑:我正在尝试获取当前运行的程序的路径，就像上面链接的问题一样。这个问题的答案是使用readlink("proc/self/exe")。我不知道如何在我的程序中实现它。我试过了：
char buf[1024];
string var = readlink("/proc/self/exe", buf, bufsize); 这显然是不正确的。
回答 4
Stack Overflow用户
回答已采纳
发布于 2011-04-03 04:38:18
此Use the readlink() function properly用于正确使用readlink函数。
如果你在std::string中有自己的路径，你可以这样做：
#include <unistd.h>
#include <limits.h>
std::string do_readlink(std::string const& path) {
char buff[PATH_MAX];
ssize_t len = ::readlink(path.c_str(), buff, sizeof(buff)-1);
if (len != -1) {
buff[len] = '\0';
return std::string(buff);
}
/* handle error condition */
}如果你只想要一条固定的路径：
std::string get_selfpath() {
char buff[PATH_MAX];
ssize_t len = ::readlink("/proc/self/exe", buff, sizeof(buff)-1);
if (len != -1) {
buff[len] = '\0';
return std::string(buff);
}
/* handle error condition */
}要使用它：
int main()
{
std::string selfpath = get_selfpath();
std::cout << selfpath << std::endl;
return 0;
}Stack Overflow用户
发布于 2011-04-03 06:02:08
让我们来看看the manpage是怎么说的：
readlink() places the contents of the symbolic link path in the buffer
buf, which has size bufsiz. readlink does not append a NUL character to
buf.好的。应该足够简单。给定1024个字符的缓冲区：
char buf[1024];
/* The manpage says it won't null terminate. Let's zero the buffer. */
memset(buf, 0, sizeof(buf));
/* Note we use sizeof(buf)-1 since we may need an extra char for NUL. */
if (readlink("/proc/self/exe", buf, sizeof(buf)-1) < 0)
{
/* There was an error... Perhaps the path does not exist
* or the buffer is not big enough. errno has the details. */
perror("readlink");
return -1;
}Stack Overflow用户
发布于 2011-07-23 03:44:36
char *
readlink_malloc (const char *filename)
{
int size = 100;
char *buffer = NULL;
while (1)
{
buffer = (char *) xrealloc (buffer, size);
int nchars = readlink (filename, buffer, size);
if (nchars < 0)
{
free (buffer);
return NULL;
}
if (nchars < size)
return buffer;
size *= 2;
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/5525668
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