Add: argument handling & PoC: echo command

src/kernel/shell.c

@@ -2,11 +2,13 @@
 #include "../libc/stdio.h"
 #include "../libc/string.h"
 #include "../programs/programs.h"
+#include "../libc/stdint.h"
 
 #define BUFFER_SIZE 256
 #define MAX_COMMANDS 16
+#define MAX_ARGS 64
 
-typedef void (*command_func_t)();
+typedef void (*command_func_t)(int argc, char *argv[]);
 
 typedef struct
 {
@@ -37,6 +39,19 @@ command_func_t find_command(const char* name)
 	return 0;
 }
 
+int parse_input(char* input, char* argv[], int max_args)
+{
+	int argc = 0;
+	char* token = strtok(input, " ");
+	while (token != NULL && argc < max_args - 1)
+	{
+		argv[argc++] = token;
+		token = strtok(NULL, " ");
+	}
+	argv[argc] = NULL;
+	return argc;
+}
+
 void shell_install()
 {
   register_command("help", program_help);
@@ -48,24 +63,26 @@ void shell_install()
   register_command("math", program_math);
   register_command("bf", program_bf);
   register_command("uptime", program_uptime);
+  register_command("echo", program_echo);
   
   for (;;)
   {
     char input_buffer[BUFFER_SIZE];
+    char* argv[MAX_ARGS];
     colorputs("blankos> ", 9);
     get_input(input_buffer, BUFFER_SIZE);
     puts("\n");
+    
+    int argc = parse_input(input_buffer, argv, MAX_ARGS);
 
-    if (strcmp(input_buffer, "") == 0) {
-    	continue;
-    }
+    if (argc == 0) continue;
 
-    command_func_t command = find_command(input_buffer);
+    command_func_t command = find_command(argv[0]);
     if (command)
     {
-	    command();
+	    command(argc, argv);
     } else {
-	    printf("Unknown command %s\n", input_buffer);
+	    printf("Unknown command %s\n", argv[0]);
     }
   }
 }

src/libc/stdint.h

@@ -17,4 +17,6 @@ typedef uint8_t bool;
 #define true 1
 #define false 0
 
+#define NULL ((void*)0)
+
 #endif

src/libc/string.c

@@ -1,3 +1,5 @@
+#include "stdint.h"
+
 int strlen(const char* str)
 {
   int len = 0;
@@ -17,3 +19,52 @@ int strcmp(const char* str1, const char* str2)
   }
   return *(const unsigned char*)str1 - *(const unsigned char*)str2;
 }
+
+char* strchr(const char* str, int c)
+{
+	while (*str)
+	{
+		if (*str == (char)c)
+		{
+			return (char*)str;
+		}
+		str++;
+	}
+	if (c == '\0')
+	{
+		return (char*)str;
+	}
+	return NULL;
+}
+
+char* strtok(char* str, const char* delimiter)
+{
+	static char* last;
+	if (str)
+	{
+		last = str;
+	} else {
+		str = last;
+	}
+
+	if (!str || *str == '\0')
+	{
+		return NULL;
+	}
+
+	char* token_start = str;
+	while (*str && !strchr(delimiter, *str))
+	{
+		str++;
+	}
+
+	if (*str)
+	{
+		*str = '\0';
+		last = str + 1;
+	} else {
+		last = NULL;
+	}
+
+	return token_start;
+}

src/libc/string.h

@@ -3,5 +3,6 @@
 
 int strlen(const char* str);
 int strcmp(const char* str1, const char* str2);
+char* strtok(char* str, const char* delimiter);
 
 #endif

src/programs/misc.c

@@ -2,6 +2,7 @@
 
 #include "../libc/stdio.h"
 #include "../kernel/system.h"
+#include "../libc/string.h"
 
 // Print a rainbow colorful text for testing
 
@@ -44,10 +45,26 @@ void program_uptime()
 
 void program_help()
 {
-	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\tuptime\n");
+	printf("help\tpanic\twords\tprimes\trainbow\tclear\nmath\tbf\tuptime\techo\n");
 }
 
+// Panic
+
 void program_panic()
 {
 	asm volatile("int $0x13");
 }
+
+// Output input
+
+void program_echo(int argc, char* argv[])
+{
+	for (int i=1; i<argc; i++)
+	{
+		puts(argv[i]);
+		if (i < argc-1) {
+			putc(' ');
+		}
+	}
+	puts("\n");
+}

src/programs/programs.h

@@ -12,4 +12,5 @@ void program_clear();
 void program_uptime();
 void program_panic();
 void program_help();
+void program_echo();
 #endif