From f29eb775b92555d14a2d8a91126c339766052ba9 Mon Sep 17 00:00:00 2001
From: Trent Huber <trentmhuber@gmail.com>
Date: Mon, 5 May 2025 03:35:49 -0400
Subject: [PATCH] Execute commands

---
 .gitignore   |  3 +++
 .gitmodules  |  3 +++
 build.c      | 10 +++++++++
 external/cbs |  1 +
 main.c       | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 76 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 .gitmodules
 create mode 100644 build.c
 create mode 160000 external/cbs
 create mode 100644 main.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3ac8fc1
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+ash
+build
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..4ab3ff4
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "external/cbs"]
+	path = external/cbs
+	url = https://github.com/trenthuber/cbs
diff --git a/build.c b/build.c
new file mode 100644
index 0000000..2ab0877
--- /dev/null
+++ b/build.c
@@ -0,0 +1,10 @@
+#include "external/cbs/cbs.c"
+
+int main(void) {
+	build(NULL);
+
+	compile("main", NULL);
+	load('x', "ash", "main", NULL);
+
+	return EXIT_SUCCESS;
+}
diff --git a/external/cbs b/external/cbs
new file mode 160000
index 0000000..47c262d
--- /dev/null
+++ b/external/cbs
@@ -0,0 +1 @@
+Subproject commit 47c262dc02e5f6ed3dba9e092a5f750084bfad95
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..eab4047
--- /dev/null
+++ b/main.c
@@ -0,0 +1,59 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/errno.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#define BUFLEN 1024
+
+char **tokenize(char *p) {
+	size_t i;
+	static char *result[BUFLEN / 2];
+
+	for (i = 0; *p != '\n'; ++i) {
+		result[i] = p;
+		while (*p != ' ' && *p != '\n') ++p;
+		*p++ = '\0';
+		if (*p == '\0') break;
+		while (*p == ' ') ++p;
+	}
+	result[i + 1] = NULL;
+	return result;
+}
+
+int main(void) {
+	char buffer[BUFLEN];
+	char **tokens;
+	pid_t cpid;
+	int status;
+
+	for (;;) {
+		printf("%% ");
+		if (fgets(buffer, BUFLEN, stdin) == NULL) {
+			if (feof(stdin)) {
+				printf("\n");
+				exit(EXIT_SUCCESS);
+			}
+			dprintf(STDERR_FILENO, "ash: Couldn't read input");
+			if (!ferror(stdin)) dprintf(STDERR_FILENO, ": %s", strerror(errno));
+			dprintf(STDERR_FILENO, "\n");
+			exit(EXIT_FAILURE);
+		}
+		tokens = tokenize(buffer);
+
+		if ((cpid = fork()) == 0)
+			if (execvp(tokens[0], tokens) == -1) {
+				dprintf(STDERR_FILENO, "ash: Unable to run command `%s': %s\n",
+				        tokens[0], strerror(errno));
+				exit(EXIT_FAILURE);
+			}
+		if (waitpid(cpid, &status, 0) == -1) {
+			dprintf(STDERR_FILENO, "ash: Unable to await command `%s': %s\n",
+			        tokens[0], strerror(errno));
+			exit(EXIT_FAILURE);
+		}
+		// TODO: Handle WIFEXITED, WIFSIGNALED, WIFSTOPPED differently
+	}
+	return 0;
+}
-- 
2.51.0