posix_spawn_file_actions - configure file actions for posix_spawn
#include <spawn.h>
typedef struct posix_spawn_file_actions_t;
int posix_spawn_file_actions_init(posix_spawn_file_actions_t*);
int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t*);
int posix_spawn_file_actions_addchdir(posix_spawn_file_actions_t*, const char*);
int posix_spawn_file_actions_addfchdir(posix_spawn_file_actions_t*, int);
int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t*, int);
int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t*, int old_fd, int new_fd);
int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t*, int fd, const char*, int flags, mode_t);Configure a posix_spawn_file_actions_t object for use with posix_spawn(2). This object can be used to let posix_spawn() set up file-related state for the spawned child process. The file actions are executed after creating the new process but before loading its binary in the order they were added to the posix_spawn_file_actions_t object.
A posix_spawn_file_actions_t object is allocated on the stack but starts in an undefined state.
posix_spawn_file_actions_init() initializes a posix_spawn_file_actions_t object that is in an undefined state and puts it in a valid state. It has to be called before the object can be passed to any other function.
posix_spawn_file_actions_destroy() frees up resources used by a valid posix_spawn_file_actions_t object and puts it into an undefined state. It has to be called after a posix_spawn_file_actions_t object is no longer needed.
It is valid to alternatingly call posix_spawn_file_actions_init() and posix_spawn_file_actions_destroy() on the same object,
posix_spawn_file_actions_addchdir() and posix_spawn_file_actions_addfchdir() make posix_spawn() change the current working directory before spawning a process, like chdir and fchdir would.. The current working directory affects the spawned child process, but also relative paths passed to later posix_spawn_file_actions_add(f)chdir() and posix_spawn_file_actions_addopen(), and relative paths passed to posix_spawn() for the executable path.
posix_spawn_file_actions_addclose() makes posix_spawn() close a file descriptor before spawning a process, like close would.
posix_spawn_file_actions_addclose() makes posix_spawn() dup a file descriptor before spawning a process, like dup2 would.
posix_spawn_file_actions_addopen() makes posix_spawn() open a file with given flags and mode, like open would, and then makes it available under fd fd to the spawned process.
In SerenityOS, these functions always succeed and return 0.
If the effect of a file action fails, the child will exit with exit code 127 before even executing the child binary.