run: Don't require the setting of POSIXLY_CORRECT on Linux

And bring this stuff out into `cmd_add_argv`.

src/bsys.c

@@ -173,15 +173,7 @@ int bsys_sh(bsys_t const* bsys, int argc, char* argv[]) {
 	}
 
 	else {
-		for (int i = 0; i < argc; i++) {
-			// On BSD/macOS, getopt doesn't consume the '--' argument.
-
-			if (strcmp(argv[i], "--") == 0) {
-				continue;
-			}
-
-			cmd_add(&cmd, argv[i]);
-		}
+		cmd_add_argv(&cmd, argc, argv);
 	}
 
 	if (cmd_exec_inplace(&cmd) < 0) {

src/bsys/bob/main.c

@@ -284,9 +284,7 @@ found:;
 	// Then, add the arguments passed to the Bob frontend.
 	// If there is no default runner, just pass the arguments from the frontend onwards.
 
-	for (ssize_t i = 0; i < argc; i++) {
-		cmd_add(&cmd, argv[i]);
-	}
+	cmd_add_argv(&cmd, argc, argv);
 
 	// Make sure there actually is something in the command.
 

src/cmd.c

@@ -71,6 +71,18 @@ __attribute__((__format__(__printf__, 2, 3))) void cmd_addf(cmd_t* cmd, char con
 	va_end(va);
 }
 
+void cmd_add_argv(cmd_t* cmd, int argc, char* argv[]) {
+	for (ssize_t i = 0; i < argc; i++) {
+		// On BSD/macOS, getopt doesn't consume the '--' argument.
+
+		if (strcmp(argv[i], "--") == 0) {
+			continue;
+		}
+
+		cmd_add(cmd, argv[i]);
+	}
+}
+
 static bool is_executable(char const* path) {
 	struct stat sb;
 

src/cmd.h

@@ -21,6 +21,7 @@ typedef struct {
 void cmd_create(cmd_t* cmd, ...);
 void cmd_add(cmd_t* cmd, char const* arg);
 __attribute__((__format__(__printf__, 2, 3))) void cmd_addf(cmd_t* cmd, char const* fmt, ...);
+void cmd_add_argv(cmd_t* cmd, int argc, char* argv[]);
 int cmd_exec_inplace(cmd_t* cmd);
 pid_t cmd_exec_async(cmd_t* cmd);
 int cmd_exec(cmd_t* cmd);