Merge branch 'master' of ssh://vo20.nl/git/uva

os/extra/src/Makefile

-CC=gcc
+CC=clang # gcc
 RM=rm -Rfv
 
 LFLAGS= -lm
@@ -21,6 +21,7 @@ shell: input.yacc.o input.lex.o main.o
 test: shell
 	 echo -n 'exit' | ./shell
 	 echo -n 'cd ../' | ./shell
+	 echo -n 'help' | ./shell
 	 echo -n 'cat input.l' | ./shell
 	 echo -n 'cat input.l | grep "id"' | ./shell
 	 echo -n '!!' | ./shell
@@ -33,7 +34,7 @@ input.yacc.h: input.yacc.c
 
 input.lex.c: input.l
 	`which flex35 2>/dev/null || which flex 2>/dev/null` \
-		-C --header-file=input.lex.h -o $@ -d $<
+		--interactive --header-file=input.lex.h -o $@ -d $<
 
 input.lex.h: input.lex.c
 

os/extra/src/input.l

 /*
- * input.l
+ * Shell input lexer (flex format).
  *
- * Shell input lexer
+ * Sander van Veen (6167969) / Taddeus Kroes (6054129).
+ * <sandervv@gmail.com>      / <taddeuskroes@hotmail.com>
  */
 
 %{
@@ -13,18 +14,18 @@
 #include "input.l.h"
 #include "input.yacc.h"
 
+// Column / line counters (used in error reporting)
 int line_no = 1, column_no = 0;
 
 extern int current_line(void){ return line_no; }
 extern int current_column(void){ return column_no; }
-
 extern void reset_line(void){ line_no = 1; }
 extern void reset_column(void){ column_no = 0; }
 
 %}
 
-%option nounput
 %option noyywrap
+%option nounput
 
 %x id
 %x num
@@ -57,13 +58,19 @@ exit {
         return EXIT;
     }
 
+    /* Help shell builtin */
+help {
+        column_no += 4;
+        return HELP;
+    }
+
     /* Change directory builtin */
 cd {
         column_no += 2;
         return CD;
     }
 
-    /* Identifiers: source */
+    /* Identifiers: source, cat, echo */
 {id} {
         column_no += yyleng;
         yylval.str = strdup(yytext);
@@ -83,14 +90,14 @@ cd {
     }
 
     /* Path or path with filename: ./a/, ../, config/, /tmp/, /tmp/file  */
-[^ ]*\/[^ ]* {
+\.*{id}?\/[^\t\n ]* {
         column_no += yyleng;
         yylval.str = strdup(yytext);
         return PATH;
     }
 
     /* Argument (filenames and such): hello.txt, .config */
-[\/{id}][^ ]+ {
+{id}[^\t\n |]+ {
         column_no += yyleng;
         yylval.str = strdup(yytext);
         return ARGUMENT;
@@ -98,22 +105,18 @@ cd {
 
 #[^\n]+ { /* ignore comments */ }
 
-    /* End of file is a separator */
-\0 {
-        line_no++;
-        reset_column();
-        return EOS;
-    }
-
     /* White space */
 \n {
         line_no++;
         reset_column();
+        shell_entry();
         return EOL;
     }
 
     /* White space */
-{wsp} { column_no++; }
+{wsp} {
+        column_no++;
+    }
 
 . {
         column_no++;

os/extra/src/input.l.h

+/*
+ * Shell function declarations.
+ *
+ * Sander van Veen (6167969) / Taddeus Kroes (6054129).
+ * <sandervv@gmail.com>      / <taddeuskroes@hotmail.com>
+ */
+
+#include "input.yacc.h"
+
+/*
+ * Helper functions for line/column counter manipulation (which are used for the
+ * lexer's error reporting).
+ */
 extern int current_line(void);
 extern int current_column(void);
+extern void reset_line();
+extern void reset_column();
 
 extern int yyparse();
 
-extern void reset_line();
-extern void reset_column();
+/*
+ * Helper functions for shell output messages.
+ */
+void shell_debug(const char *msg, ...);
+void shell_error(const char *msg);
+void shell_entry();
+
+/*
+ * Singly linked list of arguments.
+ */
+typedef struct shell_args {
+    char *arg;
+    struct shell_args *next;
+} shell_args;
+
+/*
+ * A shell command contains a function identifier and an argument list (list
+ * could be empty).
+ */
+typedef enum {FN_CD, FN_HELP, FN_EXIT, FN_EXEC} shell_func;
+
+typedef struct shell_cmd {
+    shell_func func;
+    shell_args *args;
+} shell_cmd;
+
+/*
+ * Helper functions for creating / manipulating argument objects.
+ */
+void shell_push_args(const char *value);
+void shell_append_args(const char *value);
+shell_args *shell_pop_args();
+void shell_free_args(shell_args *args);
+
+/*
+ * Builtin shell commands.
+ */
+void shell_change_dir(const char *path);
+void shell_exit();
+void shell_help();
+void shell_pipe();
+void shell_repeat(int prev);
+void shell_exec(shell_args *args);
+void shell_exec_process(shell_args *args);
+
+/*
+ * Doubly linked list containing all executed commands.
+ */
+typedef struct shell_history_log {
+    shell_cmd *cmd;
+    struct shell_history_log *prev;
+    struct shell_history_log *next;
+} shell_history_log;
+
+/*
+ * Shell history manipulation functions.
+ */
+void shell_history_add(shell_cmd *cmd);
+shell_cmd *shell_history_get(int prev);
+void shell_history_clear();
+void shell_history_append(shell_func type, shell_args *args);
 
-void start_shell_entry();
-void start_shell_pipe();

os/extra/src/input.y

 %{
 /*
- * Shell input grammar (yacc/bison format)
+ * Shell input grammar (yacc/bison format).
+ *
+ * Sander van Veen (6167969) / Taddeus Kroes (6054129).
+ * <sandervv@gmail.com>      / <taddeuskroes@hotmail.com>
  */
 
+#define YYDEBUG 1
+#define YYERROR_VERBOSE 1
+
 #include <stdio.h>
 #include <string.h>
 
-// #include "input.func.h"
 #include "input.yacc.h"
 #include "input.lex.h"
 #include "input.l.h"
 
 void yyerror(const char *str) {
-    fflush(stdout);
-    fflush(stderr);
     fprintf(stderr, "error: parser reported \"%s\" (line %d, column %d)\n", str,
             current_line(), current_column());
 
@@ -23,9 +26,10 @@ void yyerror(const char *str) {
 %}
 
 %token COMMENT IDENTIFIER ARGUMENT STRING INTEGER
-%token EOL EOS CD EXIT PATH
+%token EOL EOS CD EXIT PATH HELP
 
-%type <str> PATH INTEGER
+%type <str> PATH INTEGER IDENTIFIER ARGUMENT STRING
+%type <str> Argument
 
 %union {
     char * str;
@@ -35,29 +39,31 @@ void yyerror(const char *str) {
 
 %%
 
-Start: /* empty */
-    | Commands
+Start: Commands
     ;
 
-Commands: Command  /*{ printf("cmd: %s\n", $1); }*/
-/*    | Command EOS*/
-    | Commands EOL { start_shell_entry(); } Command
-    | Commands '|' { start_shell_pipe(); } Command
+Commands: Command
+    | Commands EOL Command
+    | Commands '|' { shell_pipe(); } Command
     ;
 
-Command: Builtin
-    | IDENTIFIER
-    | IDENTIFIER Arguments
+Command: /* Empty */
+    | Builtin
+    | IDENTIFIER { shell_push_args($1); }
+                 { shell_exec(shell_pop_args()); }
+    | IDENTIFIER { shell_push_args($1); }
+      Arguments  { shell_exec(shell_pop_args()); }
     ;
 
-Builtin: EXIT       { puts("Exit shell"); }
-    | CD PATH       { printf("CD %s\n", $2); }
-    | '!' '!'       { puts("Repeat last"); }
-    | '!' INTEGER   { printf("Repeat %d\n", atoi($2)); }
+Builtin: EXIT     { shell_exit(); }
+    | HELP        { shell_help(); }
+    | CD Argument { shell_change_dir($2); }
+    | '!' '!'     { shell_repeat(1); }
+    | '!' INTEGER { shell_repeat(atoi($2)); }
     ;
 
- Arguments: Argument
-    | Arguments ' ' Argument
+Arguments: Argument      { shell_append_args($1); }
+    | Arguments Argument { shell_append_args($2); }
     ;
 
 Argument: STRING