The branch main has been updated by kevans:
URL:
https://cgit.FreeBSD.org/src/commit/?id=3f0e1092097ed63b83a02518395e370c3cac01be
commit 3f0e1092097ed63b83a02518395e370c3cac01be
Author: Kyle Evans <kev...@freebsd.org>
AuthorDate: 2025-07-09 05:12:32 +0000
Commit: Kyle Evans <kev...@freebsd.org>
CommitDate: 2025-07-09 05:12:32 +0000
flua: fbsd: allow stdout to be captured for exec() processes
This allows us to do things like:
```
local fp = assert(fbsd.exec({"ls", "-l"}, true))
local fpout = assert(fp:stdout())
while true do
local line = fpout:read("l")
if not line then break end
print("Read: " .. line)
end
fp:close()
```
The makeman lua rewrite will use it to capture `make showconfig` output
for processing.
Reviewed by: bapt
Differential Revision: https://reviews.freebsd.org/D50539
---
libexec/flua/modules/lfbsd.c | 95 ++++++++++++++++++++++++++++++++++++++------
1 file changed, 82 insertions(+), 13 deletions(-)
diff --git a/libexec/flua/modules/lfbsd.c b/libexec/flua/modules/lfbsd.c
index a361fa25601b..ef660ba9fd77 100644
--- a/libexec/flua/modules/lfbsd.c
+++ b/libexec/flua/modules/lfbsd.c
@@ -31,6 +31,7 @@
#include <errno.h>
#include <fcntl.h>
#include <spawn.h>
+#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
@@ -44,6 +45,7 @@
struct fbsd_process {
int pid;
int stdin_fileno;
+ int stdout_fileno;
};
extern char **environ;
@@ -70,6 +72,16 @@ luaL_checkarraystrings(lua_State *L, int arg)
return ret;
}
+static void
+close_pipes(int pipes[2])
+{
+
+ if (pipes[0] != -1)
+ close(pipes[0]);
+ if (pipes[1] != -1)
+ close(pipes[1]);
+}
+
static int
lua_exec(lua_State *L)
{
@@ -77,31 +89,57 @@ lua_exec(lua_State *L)
int r;
posix_spawn_file_actions_t action;
int stdin_pipe[2] = {-1, -1};
+ int stdout_pipe[2] = {-1, -1};
pid_t pid;
const char **argv;
int n = lua_gettop(L);
- luaL_argcheck(L, n == 1, n > 1 ? 2 : n,
- "fbsd.exec takes exactly one argument");
+ bool capture_stdout;
+ luaL_argcheck(L, n > 0 && n <= 2, n >= 2 ? 2 : n,
+ "fbsd.exec takes exactly one or two arguments");
+ capture_stdout = lua_toboolean(L, 2);
if (pipe(stdin_pipe) < 0) {
lua_pushnil(L);
lua_pushstring(L, strerror(errno));
lua_pushinteger(L, errno);
return (3);
}
+ if (capture_stdout && pipe(stdout_pipe) < 0) {
+ close_pipes(stdin_pipe);
+ lua_pushnil(L);
+ lua_pushstring(L, strerror(errno));
+ lua_pushinteger(L, errno);
+ return (3);
+ }
proc = lua_newuserdata(L, sizeof(*proc));
proc->stdin_fileno = stdin_pipe[1];
-
+ proc->stdout_fileno = stdout_pipe[1];
posix_spawn_file_actions_init(&action);
posix_spawn_file_actions_adddup2(&action, stdin_pipe[0], STDIN_FILENO);
posix_spawn_file_actions_addclose(&action, stdin_pipe[1]);
+ if (stdin_pipe[0] != STDIN_FILENO)
+ posix_spawn_file_actions_addclose(&action, stdin_pipe[0]);
+
+ /*
+ * Setup stdout to be captured if requested. Otherwise, we just let it
+ * go to our own stdout.
+ */
+ if (stdout_pipe[0] != -1) {
+ posix_spawn_file_actions_adddup2(&action, stdout_pipe[0],
+ STDOUT_FILENO);
+ posix_spawn_file_actions_addclose(&action, stdout_pipe[1]);
+ if (stdout_pipe[0] != STDOUT_FILENO) {
+ posix_spawn_file_actions_addclose(&action,
+ stdout_pipe[0]);
+ }
+ }
argv = luaL_checkarraystrings(L, 1);
if (0 != (r = posix_spawnp(&pid, argv[0], &action, NULL,
(char*const*)argv, environ))) {
- close(stdin_pipe[0]);
- close(stdin_pipe[1]);
+ close_pipes(stdin_pipe);
+ close_pipes(stdout_pipe);
posix_spawn_file_actions_destroy(&action);
lua_pop(L, 2); /* Pop off the process handle and args. */
@@ -114,12 +152,14 @@ lua_exec(lua_State *L)
lua_pop(L, 1);
close(stdin_pipe[0]);
+ if (stdout_pipe[0] != -1)
+ close(stdout_pipe[0]);
posix_spawn_file_actions_destroy(&action);
proc->pid = pid;
luaL_setmetatable(L, FBSD_PROCESSHANDLE);
- return 1;
+ return (1);
}
static int
@@ -144,24 +184,34 @@ lua_process_close(lua_State *L)
return (2);
}
- if (proc->stdin_fileno >= 0)
+ if (proc->stdin_fileno >= 0) {
close(proc->stdin_fileno);
- proc->stdin_fileno = -1;
+ proc->stdin_fileno = -1;
+ }
+
+ if (proc->stdout_fileno >= 0) {
+ close(proc->stdout_fileno);
+ proc->stdout_fileno = -1;
+ }
lua_pushboolean(L, 1);
- return 1;
+ return (1);
}
static int
-lua_process_stdin(lua_State *L)
+lua_process_makestdio(lua_State *L, int fd, const char *mode)
{
- struct fbsd_process *proc;
luaL_Stream *p;
FILE *fp;
int r;
- proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
- fp = fdopen(proc->stdin_fileno, "w");
+ if (fd == -1) {
+ lua_pushnil(L);
+ lua_pushstring(L, "Stream not captured");
+ return (2);
+ }
+
+ fp = fdopen(fd, mode);
if (fp == NULL) {
r = errno;
@@ -178,10 +228,29 @@ lua_process_stdin(lua_State *L)
return (1);
}
+static int
+lua_process_stdin(lua_State *L)
+{
+ struct fbsd_process *proc;
+
+ proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
+ return (lua_process_makestdio(L, proc->stdin_fileno, "w"));
+}
+
+static int
+lua_process_stdout(lua_State *L)
+{
+ struct fbsd_process *proc;
+
+ proc = luaL_checkudata(L, 1, FBSD_PROCESSHANDLE);
+ return (lua_process_makestdio(L, proc->stdout_fileno, "r"));
+}
+
#define PROCESS_SIMPLE(n) { #n, lua_process_ ## n }
static const struct luaL_Reg fbsd_process[] = {
PROCESS_SIMPLE(close),
PROCESS_SIMPLE(stdin),
+ PROCESS_SIMPLE(stdout),
{ NULL, NULL },
};
