Shell-VII release

1 files changed, 113 insertions, 39 deletions

diff --git a/lexical_analysis.c b/lexical_analysis.c
index 5db57cb..eab4390 100644
--- a/lexical_analysis.c
+++ b/lexical_analysis.c
@@ -46,11 +46,39 @@ int is_empty_word(int ch, struct param_type params)
             params.empty_word_flag;
 }
 
-int command_execution_condition(struct param_type *params)
+static int find_end_subshell_before_cur_pos(struct readline_type *readline)
 {
+    int i;
+    for(i = readline->considered_index-1; i >= 0; --i) {
+        if(readline->arr[i] == ' ')
+            continue;
+        break;
+    }
+    return i >= 0 && readline->arr[i] == ')';
+}
+
+int command_execution_condition(struct param_type *params,
+                                struct readline_type *readline)
+{
+    if(params->tokens == and || params->tokens == or) {
+        if(find_end_subshell_before_cur_pos(readline))
+            return 0;
+    }
+    if(params->tokens == next_command) {
+        if(find_end_subshell_before_cur_pos(readline))
+            return 0;
+    }
+    if(params->tokens == '&') {
+        if(find_end_subshell_before_cur_pos(readline))
+            return 0;
+    }
+    if(params->tokens == '(' && params->pipeline)
+        return 1;
+
     return
         (params->tokens != '<' && params->tokens != '>' &&
-                params->tokens != append && !params->pipeline) ||
+        params->tokens != append && !params->pipeline &&
+        params->tokens != start_subshell) ||
         (params->pipeline && params->tokens == '&');
 }
 
@@ -59,24 +87,24 @@ int is_first_special_token_character(int ch)
     return ch == '<' || ch == '>' || ch == '&' || ch == '|' || ch == ';';
 }
 
-int excessive_words(int ch, struct param_type *params)
+int excessive_words(int ch, struct param_type *params,
+                    struct readline_type *readline)
 {
-    int next_ch;
-
     if(filename_waiting(params)) {
         if(ch == new_line)
             return 0;
-        while((next_ch = getchar()) != new_line) {
-            if(next_ch == ' ')
-                continue;
-            if(!is_first_special_token_character(next_ch)) {
+        int i;
+        for(i = readline->considered_index+1; i <= readline->last_element_index;
+                                                                        ++i)
+        {
+            if(readline->arr[i] == ' ')
+                    continue;
+            if(!is_first_special_token_character(readline->arr[i])) {
                 params->wrong_command = err_extra_chars_after_filename;
                 return 1;
-            }
-            else
+            } else
                 break;
         }
-        ungetc(next_ch, stdin);
     }
     return 0;
 }
@@ -101,16 +129,10 @@ int validate_redirections(int ch, int next_ch, struct param_type *params)
              params->streams.output_stream_to_append == NULL);
 }
 
-int is_double_token(struct param_type *params)
-{
-    return params->tokens == and || params->tokens == or ||
-            params->tokens == append;
-}
-
 int is_special_token(int ch, int next_ch)
 {
-    return (ch == '&' && next_ch == '&') || (ch == '|' && ch == '|') ||
-            ch == '&' || ch == ';' || ch == '|';
+    return (ch == '&' && next_ch == '&') || (ch == '|' && next_ch == '|') ||
+            ch == '&' || ch == ';' || ch == '|' || ch == '(' || ch == ')';
 }
 
 int is_redirect_token(int ch, int next_ch)
@@ -139,8 +161,8 @@ int stream_redirect_tokens(struct w_queue *word_chain,
 
         if(validate_redirections(ch, next_ch, params)) {
             params->tokens = (ch == '>' && next_ch == '>') ? append : ch;
-            if(is_double_token(params))
-                ++readline->considered_index;
+            if(params->tokens == append)
+                readline->considered_index += 2;
             return 1;
         } else
             params->wrong_command = err_redirect_stream_again;
@@ -167,12 +189,20 @@ int pipeline_token_processing(struct w_queue *word_chain,
                               struct dynamic_array *tmp_word,
                               struct param_type *params)
 {
+    /* pipeline after subshell */
+    if(tmp_word->last_element_index == -1 && params->tokens == start_subshell) {
+        params->tokens = '|';
+        params->pipeline = 1;
+        return 1;
+    }
+
     char **cmdline = NULL;
     if(is_stream_redirection_set(params) &&
             wrong_streams_redirection(params)) {
         params->wrong_command = err_redirect_stream_in_pipeline;
         return 0;
     }
+
     params->tokens = '|';
     params->pipeline = 1;
     cmdline =
@@ -184,44 +214,88 @@ int pipeline_token_processing(struct w_queue *word_chain,
     return 1;
 }
 
+static void stop_by_previous_effect_tokens(struct param_type *params)
+{
+    if((params->tokens == and && last_execution_status == 1) ||
+            (params->tokens == or && last_execution_status == 0))
+        params->wrong_command = err_set_failure;
+}
+
+static int find_repeated_background_symbol(struct readline_type *readline)
+{
+    int i;
+    for(i = readline->considered_index + 1; i <= readline->last_element_index;
+                                                                        ++i)
+    {
+        if(readline->arr[i] == '&')
+            return 1;
+    }
+    return 0;
+}
+
 /*
  * verification of special tokens (|, &, &&, ||), except redirection tokens
  */
 int special_tokens(struct w_queue *word_chain, struct c_queue *cmdlines,
-                   struct dynamic_array *tmp_word, int ch,
+                   struct dynamic_array *tmp_word, int *ch,
                    struct param_type *params, struct readline_type *readline)
 {
     int next_ch, i;
-
-    if(ch == '|' || ch == '&')
+    if(*ch == '|' || *ch == '&')
         next_ch = readline->arr[readline->considered_index + 1];
 
-    if(is_special_token(ch, next_ch)) {
+    if(is_special_token(*ch, next_ch)) {
         add_word_or_filename(word_chain, tmp_word, params);
+        stop_by_previous_effect_tokens(params);
 
         if(params->wrong_command)
             return 0;
 
-        if(ch == '|' && next_ch == '|')
+        if(*ch == '|' && next_ch == '|') {
             params->tokens = or;
-        else if(ch == '|') {
-            if(!pipeline_token_processing(word_chain, cmdlines, tmp_word,
-                                          params))
-                return 0;
-        } else if(ch == '&' && next_ch == '&')
+            readline->considered_index += 2;
+            return 1;
+        }
+        if(*ch == '|')
+            return pipeline_token_processing(word_chain, cmdlines, tmp_word,
+                                             params);
+        if(*ch == '&' && next_ch == '&') {
             params->tokens = and;
-        else if(ch == '&') {
+            readline->considered_index += 2;
+            return 1;
+        }
+        if(*ch == '&') {
+            /* repeated & */
+            if(find_repeated_background_symbol(readline)) {
+                params->wrong_command = err_repeated_background_ch;
+                return 0;
+            }
+
             for(i = readline->considered_index+1; readline->arr[i] != new_line;
                                                                         ++i) {
-                if(readline->arr[i] != whitespace && readline->arr[i] != tab) {
-                    params->wrong_command = err_bg_process;
-                    return 0;
-                }
+                if(readline->arr[i] == ' ')
+                    continue;
+                else
+                    break;
             }
+            if(readline->arr[i] == new_line)
+                *ch = new_line;
             params->tokens = '&';
+            return 1;
+        }
+        if(*ch == start_subshell) {
+            params->tokens = start_subshell;
+            return 1;
+        }
+        if(*ch == end_subshell) {
+            params->tokens = end_subshell;
+            return 1;
         }
-        if(is_double_token(params))
-            ++readline->considered_index;
+        if(*ch == next_command) {
+            params->tokens = next_command;
+            return 1;
+        }
+
         return 1;
     }
     return 0;