Accessing File Group ID (GID) in Go

In Go, the os.Stat() function retrieves file information, including its system-specific attributes. This information is stored in a syscall.Sys interface. While printing the interface directly reveals the GID, accessing it programmatically poses a challenge.

To obtain the GID as a string for Linux systems:

file_info, _ := os.Stat(abspath)
file_sys := file_info.Sys()
file_gid := fmt.Sprint(file_sys.(*syscall.Stat_t).Gid)

The Sys() interface returns a pointer to syscall.Stat_t. Casting the interface to *syscall.Stat_t allows access to the Gid field. Converting the result to a string using fmt.Sprint() returns the GID as a string.

Alternatively, to access the GID as an integer:

file_gid := int64(file_sys.(*syscall.Stat_t).Gid)

Casting the interface to *syscall.Stat_t and extracting the Gid field returns the GID as an integer.

Please note that this method relies on internal implementation details of Go's syscall package. It is recommended to use the standard os or io packages for file operations whenever possible.