| Technical Specification | ||||
| Filesystem library(filesystem TS) | ||||
| Library fundamentals(library fundamentals TS) | ||||
| Library fundamentals 2(library fundamentals TS v2) | ||||
| Library fundamentals 3(library fundamentals TS v3) | ||||
| Extensions for parallelism(parallelism TS) | ||||
| Extensions for parallelism 2(parallelism TS v2) | ||||
| Extensions for concurrency(concurrency TS) | ||||
| Extensions for concurrency 2(concurrency TS v2) | ||||
| Concepts(concepts TS) | ||||
| Ranges(ranges TS) | ||||
| Reflection(reflection TS) | ||||
| Mathematical special functions(special functions TR) | ||||
| Experimental Non-TS | ||||
| Pattern Matching | ||||
| Linear Algebra | ||||
| std::execution | ||||
| Contracts | ||||
| 2D Graphics |
| Classes | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Functions | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| File types | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Defined in header <experimental/filesystem> | ||
bool is_socket( file_status s); | (1) | (filesystem TS) |
bool is_socket(const path& p); bool is_socket(const path& p, error_code& ec); | (2) | (filesystem TS) |
Checks if the given file status or path corresponds to a named IPC socket, as if determined by the POSIXS_IFSOCK.
Contents |
| s | - | file status to check |
| p | - | path to examine |
| ec | - | out-parameter for error reporting in the non-throwing overload |
true if the file indicated byp or if the type indicateds refers to a named socket. The non-throwing overload returnsfalse if an error occurs.
Named sockets are UNIX domain sockets constructed withsocket andbind POSIX APIs, which may be used for advanced interprocess communication. In particular, they may be used to transport open file descriptors from one running process to another.
The information provided by this function is usually also provided as a byproduct of directory iteration. During directory iteration, callingis_socket(*iterator) is less efficient thanis_socket(iterator->status()).
#include <cstdio>#include <cstring>#include <experimental/filesystem>#include <fstream>#include <iostream>#include <sys/socket.h>#include <sys/stat.h>#include <sys/un.h>#include <unistd.h> namespace fs= std::experimental::filesystem; void demo_status(const fs::path& p, fs::file_status s){std::cout<< p;// alternative: switch(s.type()) { case fs::file_type::regular: ... }if(fs::is_regular_file(s))std::cout<<" is a regular file\n";if(fs::is_directory(s))std::cout<<" is a directory\n";if(fs::is_block_file(s))std::cout<<" is a block device\n";if(fs::is_character_file(s))std::cout<<" is a character device\n";if(fs::is_fifo(s))std::cout<<" is a named IPC pipe\n";if(fs::is_socket(s))std::cout<<" is a named IPC socket\n";if(fs::is_symlink(s))std::cout<<" is a symlink\n";if(!fs::exists(s))std::cout<<" does not exist\n";} int main(){// create files of different kinds fs::create_directory("sandbox");std::ofstream("sandbox/file");// create regular file fs::create_directory("sandbox/dir"); mkfifo("sandbox/pipe",0644);struct sockaddr_un addr; addr.sun_family= AF_UNIX;std::strcpy(addr.sun_path,"sandbox/sock");int fd= socket(PF_UNIX, SOCK_STREAM,0); bind(fd,(struct sockaddr*)&addr, sizeof addr); fs::create_symlink("file","sandbox/symlink"); // demo different status accessorsfor(auto it= fs::directory_iterator("sandbox"); it!= fs::directory_iterator();++it) demo_status(*it, it->symlink_status());// use cached status from directory entry demo_status("dev/null", fs::status("/dev/null"));// direct calls to status demo_status("dev/sda", fs::status("/dev/sda")); demo_status("sandbox/no", fs::status("/sandbox/no")); // cleanup close(fd); fs::remove_all("sandbox");}
Possible output:
"sandbox/file" is a regular file"sandbox/dir" is a directory"sandbox/pipe" is a named IPC pipe"sandbox/sock" is a named IPC socket"sandbox/symlink" is a symlink"dev/null" is a character device"dev/sda" is a block device"sandbox/no" does not exist
| determines file attributes determines file attributes, checking the symlink target (function)[edit] | |
| represents file type and permissions (class)[edit] | |
| checks whether file status is known (function)[edit] | |
| checks whether the given path refers to block device (function)[edit] | |
| checks whether the given path refers to a character device (function)[edit] | |
| checks whether the given path refers to a directory (function)[edit] | |
| checks whether the given path refers to a named pipe (function)[edit] | |
| checks whether the argument refers to another file (function)[edit] | |
| checks whether the argument refers to a regular file (function)[edit] | |
| checks whether the argument refers to a symbolic link (function)[edit] | |
| checks whether path refers to existing file system object (function)[edit] | |
| cached status of the file designated by this directory entry cached symlink_status of the file designated by this directory entry (public member function of std::experimental::filesystem::directory_entry)[edit] |