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Defined in header <filesystem> | ||
void create_symlink(conststd::filesystem::path& target, conststd::filesystem::path& link); | (1) | (since C++17) |
void create_symlink(conststd::filesystem::path& target, conststd::filesystem::path& link, | (2) | (since C++17) |
void create_directory_symlink(conststd::filesystem::path& target, conststd::filesystem::path& link); | (3) | (since C++17) |
void create_directory_symlink(conststd::filesystem::path& target, conststd::filesystem::path& link, | (4) | (since C++17) |
Creates a symbolic linklink with its target set totarget as if by POSIXsymlink(): the pathnametarget may be invalid or non-existing.
Some operating systems require symlink creation to identify that the link is to a directory. Portable code should use(3,4) to create directory symlinks rather than(1,2), even though there is no distinction on POSIX systems.
Contents |
| target | - | path to point the symlink to, does not have to exist |
| link | - | path of the new symbolic link |
| ec | - | out-parameter for error reporting in the non-throwing overload |
(none)
Any overload not markednoexcept may throwstd::bad_alloc if memory allocation fails.
Some operating systems do not support symbolic links at all or support them only for regular files.
Some file systems do not support symbolic links regardless of the operating system, for example the FAT system used on some memory cards and flash drives.
Like a hard link, a symbolic link allows a file to have multiple logical names. The presence of a hard link guarantees the existence of a file, even after the original name has been removed. A symbolic link provides no such assurance; in fact, the file named by thetarget argument need not exist when the link is created. A symbolic link can cross file system boundaries.
#include <cassert>#include <filesystem>#include <iostream>namespace fs= std::filesystem; int main(){ fs::create_directories("sandbox/subdir"); fs::create_symlink("target","sandbox/sym1"); fs::create_directory_symlink("subdir","sandbox/sym2"); for(auto it= fs::directory_iterator("sandbox"); it!= fs::directory_iterator();++it)if(is_symlink(it->symlink_status()))std::cout<<*it<<"->"<< read_symlink(*it)<<'\n'; assert(std::filesystem::equivalent("sandbox/sym2","sandbox/subdir")); fs::remove_all("sandbox");}
Possible output:
"sandbox/sym1"->"target""sandbox/sym2"->"subdir"
(C++17)(C++17) | determines file attributes determines file attributes, checking the symlink target (function)[edit] |
(C++17) | obtains the target of a symbolic link (function)[edit] |
(C++17) | creates a hard link (function)[edit] |