Add nohup implementation

corebuf/nohup.c

@@ -0,0 +1,51 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+#define or ||
+#define GetFile(X) open(X, O_APPEND|O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR)
+
+static inline bool
+die(const char *errstr, int errcode)
+{
+	fprintf(stderr, "%s\n", errstr);
+	exit(errcode);
+	return 0;//dummy return
+}
+
+int
+main(int argc, char *argv[])
+{
+	const char *fname = "nohup.out";
+	const char *usage = "usage: nohup <cmd [<args...>]";
+	char dest[PATH_MAX];
+	char *home;
+	int fd;
+
+	argv++;
+	argc > 1
+		or die(usage, EXIT_FAILURE);
+	signal(SIGHUP, SIG_IGN) != SIG_ERR
+		or die("signal(2)", 126);
+	if (isatty(STDOUT_FILENO)) {
+		if ((fd = GetFile(fname)) == -1) {
+			home = getenv("HOME");
+			if (home)
+				snprintf(dest, sizeof(dest), "%s/%s", home, fname);
+			else
+				strcpy(dest, fname);
+			if ((fd = GetFile(fname)) == -1)
+				return 126;
+			dup2(fd, STDOUT_FILENO);
+		}
+	}
+	if (isatty(STDERR_FILENO))
+		dup2(STDOUT_FILENO, STDERR_FILENO);
+	execvp(*argv, argv);
+	exit(126+(errno == ENOENT));
+}

src/main.cpp

@@ -106,7 +106,7 @@ typedef std::string CodeBlock;
 typedef std::string AliasName;
 typedef std::string Path;
 typedef int Jid;
-#define DispatchTable std::unordered_map
+#define DispatchTable std::map
 /***** GLOBAL VARIABLES BEGIN *****/
   extern char **environ;