From 7536d000ac9a5188378f2749ecfd7f0ccb437573 Mon Sep 17 00:00:00 2001
From: Nathan Reiner <nathan@nathanreiner.xyz>
Date: Wed, 14 Dec 2022 22:12:20 +0100
Subject: first try to pipe stuff

---
 smash/Makefile |   2 +-
 smash/parser.c |  81 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
 smash/parser.h |   7 +----
 smash/test     | Bin 0 -> 26656 bytes
 4 files changed, 73 insertions(+), 17 deletions(-)
 create mode 100755 smash/test

(limited to 'smash')

diff --git a/smash/Makefile b/smash/Makefile
index 3f684cd..4deb244 100644
--- a/smash/Makefile
+++ b/smash/Makefile
@@ -1,5 +1,5 @@
 unit_test_parser:
-	gcc parser.c ../lib/cstr/cstr.c ../lib/malloc/malloc.c ../lib/sys/start.S -static -nostdlib -fno-stack-protector -o test -DPARSER_UNIT_TEST -g
+	gcc parser.c ../lib/cstr/cstr.c ../lib/malloc/malloc.c ../lib/sys/start.S -static -nostdlib -fno-stack-protector -Wno-implicit-function-declaration -o test -DPARSER_UNIT_TEST -g
 	./test
 
 unit_test_variables:
diff --git a/smash/parser.c b/smash/parser.c
index 33fb410..22b9ccf 100644
--- a/smash/parser.c
+++ b/smash/parser.c
@@ -14,21 +14,44 @@ expression_list_t *new_expression_from_line(char *line)
 	u64 n = cstr_split(line, '|');
 	char *current = line;
 	char *next    = 0;
-
+	expression_list_t *head = 0;
+	expression_list_t *expression = 0;
 
 	for (; n > 0; --n) {
 		next = (char*)next_split(current);
 
 		strip_cstr(current, ' ');
 
-		write(0, current, cstr_length(current));
-		write(0, "\\n\n", 3);
+		if (!expression) {
+			expression = malloc(sizeof(expression_list_t));
+			head = expression;
+		} else {
+			expression->next = malloc(sizeof(expression_list_t));
+			expression = expression->next;
+		}
+
+		expression->call = current;
+		expression->next = 0;
 
 		current = next;
 	}
-	return 0;
+
+	return head;
 }
 
+
+void free_expression(expression_list_t *expression)
+{
+	expression_list_t *next;
+
+	while (expression) {
+		next = expression->next;
+		free(expression);
+		expression = next;
+	}
+}
+
+
 char **__new_argv(char *exp)
 {
 	u64 n = cstr_split(exp, ' ');
@@ -61,16 +84,54 @@ void __free_argv(char **argv)
 #ifdef PARSER_UNIT_TEST
 
 #include "../lib/sys/execve.h"
+#include "../lib/sys/fork.h"
+#include "../lib/sys/wait4.h"
+#include "../lib/sys/pipe.h"
+#include "../lib/sys/dup2.h"
+#include "../lib/sys/close.h"
+#include "../lib/sys/io.h"
+#include "../lib/sys/exit.h"
 
 int main() {
-	const char exp[] = "/bin/ls -a -l -h";
-	char **argv = __new_argv(exp);
-	char **p = argv;
-	char *const envp[] = { 0 };
+	char in[] = "/bin/ls -a | /bin/wc -l";
+	expression_list_t *exps = new_expression_from_line(in);
+	expression_list_t *exp = exps;
+	char **envp = { 0 };
 
-	execve(argv[0], argv, envp);
+	int pid[2];
+	int pipefd[2];
 
-	free(argv);
+	char **argv1 = __new_argv(exp->call);
+	char **argv2 = __new_argv(exp->next->call);
+
+	pipe(pipefd);
+	pid[0] = fork();
+
+	if (pid[0] == 0) {
+		close(pipefd[0]);
+		dup2(pipefd[1], STDOUT_FD);
+		close(pipefd[1]);
+
+		execve(argv1[0], argv1, envp);
+	} else {
+		pid[1] = fork();
+
+
+		close(pipefd[1]);
+
+		if (pid[1] == 0) {
+			dup2(pipefd[0], STDIN_FD);
+			close(pipefd[0]);
+
+			execve(argv2[0], argv2, envp);
+		} else {
+			close(pipefd[0]);
+			wait4(pid[0], 0, 0);
+			wait4(pid[1], 0, 0);
+		}
+	}
+
+	return 0;
 }
 
 #endif
diff --git a/smash/parser.h b/smash/parser.h
index 9c23e0f..23eee88 100644
--- a/smash/parser.h
+++ b/smash/parser.h
@@ -3,13 +3,8 @@
 
 #include "../lib/sys/sizes.h"
 
-typedef struct {
-	const char *head;
-	const char **args;
-} expression_t;
-
 typedef struct expression_list_t__ {
-	expression_t               expression;
+	char                       *call;
 	struct expression_list_t__ *next;
 } expression_list_t;
 
diff --git a/smash/test b/smash/test
new file mode 100755
index 0000000..a76addd
Binary files /dev/null and b/smash/test differ
-- 
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