1 files changed, 86 insertions, 2 deletions

diff --git a/jim-posix.c b/jim-posix.c
index e8cb6e6..e199848 100644
--- a/jim-posix.c
+++ b/jim-posix.c
@@ -19,6 +19,7 @@
 
 #include <sys/types.h>
 #include <sys/time.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include <string.h>
 #include <signal.h>
@@ -47,7 +48,7 @@ static int Jim_PosixForkCommand(Jim_Interp *interp, int argc,
         return JIM_ERR;
     }
     if ((pid = fork()) == -1) {
-        Jim_SetResultString(interp, strerror(errno), -1);
+        Jim_PosixSetError(interp);
         return JIM_ERR;
     }
     Jim_SetResult(interp, Jim_NewIntObj(interp, (jim_wide)pid));
@@ -55,6 +56,89 @@ static int Jim_PosixForkCommand(Jim_Interp *interp, int argc,
 #endif
 }
 
+/*
+ * os.wait ?-nohang? pid
+ *
+ * An interface to waitpid(2)
+ *
+ * Returns a 3 element list.
+ *
+ * If -nohang is specified, and the process is still alive, returns
+ *
+ *   {0 none 0}
+ * 
+ * If the process does not exist or has already been waited for, returns:
+ *
+ *   {-1 error <error-description>} 
+ *
+ * If the process exited normally, returns:
+ *
+ *   {<pid> exit <exit-status>} 
+ *
+ * If the process terminated on a signal, returns:
+ *
+ *   {<pid> signal <signal-number>} 
+ *
+ * Otherwise (core dump, stopped, continued, ...), returns:
+ *
+ *   {<pid> other 0}
+ */
+static int Jim_PosixWaitCommand(Jim_Interp *interp, int argc, 
+        Jim_Obj *const *argv)
+{
+    int nohang = 0;
+    long pid;
+    int status;
+    Jim_Obj *listObj;
+    const char *type;
+    int value;
+
+    if (argc > 1 && Jim_CompareStringImmediate(interp, argv[1], "-nohang")) {
+        nohang = 1;
+    }
+    if (argc != nohang + 2) {
+        Jim_WrongNumArgs(interp, 1, argv, "?-nohang? pid");
+        return JIM_ERR;
+    }
+    if (Jim_GetLong(interp, argv[nohang + 1], &pid) != JIM_OK) {
+        return JIM_ERR;
+    }
+
+    pid = waitpid(pid, &status, nohang ? WNOHANG : 0);
+    listObj = Jim_NewListObj(interp, NULL, 0);
+    Jim_ListAppendElement(interp, listObj, Jim_NewIntObj(interp, pid));
+    if (pid < 0) {
+        type = "error";
+        value = errno;
+    }
+    else if (pid == 0) {
+        type = "none";
+        value = 0;
+    }
+    else if (WIFEXITED(status)) {
+        type = "exit";
+        value = WEXITSTATUS(status);
+    }
+    else if (WIFSIGNALED(status)) {
+        type = "signal";
+        value = WTERMSIG(status);
+    }
+    else {
+        type = "other";
+        value = 0;
+    }
+
+    Jim_ListAppendElement(interp, listObj, Jim_NewStringObj(interp, type, -1));
+    if (pid < 0) {
+        Jim_ListAppendElement(interp, listObj, Jim_NewStringObj(interp, strerror(value), -1));
+    }
+    else {
+        Jim_ListAppendElement(interp, listObj, Jim_NewIntObj(interp, value));
+    }
+    Jim_SetResult(interp, listObj);
+    return JIM_OK;
+}
+
 static int Jim_PosixGetidsCommand(Jim_Interp *interp, int argc,
         Jim_Obj *const *argv)
 {
@@ -104,12 +188,12 @@ static int Jim_PosixPidCommand(Jim_Interp *interp, int argc, Jim_Obj *const *arg
     return JIM_OK;
 }
 
-// end added 
 int Jim_posixInit(Jim_Interp *interp)
 {
     if (Jim_PackageProvide(interp, "posix", "1.0", JIM_ERRMSG) != JIM_OK)
         return JIM_ERR;
     Jim_CreateCommand(interp, "os.fork", Jim_PosixForkCommand, NULL, NULL);
+    Jim_CreateCommand(interp, "os.wait", Jim_PosixWaitCommand, NULL, NULL);
     Jim_CreateCommand(interp, "os.getids", Jim_PosixGetidsCommand, NULL, NULL);
     Jim_CreateCommand(interp, "os.gethostname", Jim_PosixGethostnameCommand, NULL, NULL);
     Jim_CreateCommand(interp, "pid", Jim_PosixPidCommand, NULL, NULL);