Shell-edit release

Autocomplete program and file names (tab).
Moving the cursor to edit commands (left and right arrows).
Deleting a character in a command (backspace).

1 files changed, 150 insertions, 23 deletions

diff --git a/shell.c b/shell.c
index 71be7fd..2944f00 100644
--- a/shell.c
+++ b/shell.c
@@ -2,6 +2,8 @@
 #include "queue.h"
 #include "dynamic_array.h"
 #include "lexical_analysis.h"
+#include "file_suggestions.h"
+#include "readline.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -11,6 +13,7 @@
 #include <fcntl.h>
 #include <signal.h>
 #include <errno.h>
+#include <termios.h>
 
 MAKE_QUEUE_INIT(w_queue)
 MAKE_QUEUE_INIT(p_queue)
@@ -23,6 +26,7 @@ enum modes { word_separation, whole_word };
 static void show_invitation()
 {
     printf("> ");
+    fflush(stdout);
 }
 
 /* remove background zombie processes */
@@ -54,6 +58,7 @@ static void init_params(struct param_type *params, enum modes *current_mode)
     /* 0 - success, 1 - error */
     params->last_execution_status = 0;
     params->pipeline = 0;
+    params->new_readline = 1;
     *current_mode = word_separation;
 }
 
@@ -74,11 +79,13 @@ static void reset_params(struct param_type *params,
                          enum modes *current_mode,
                          struct w_queue *word_chain,
                          struct c_queue *cmdlines,
-                         struct dynamic_array *tmp_word)
+                         struct dynamic_array *tmp_word,
+                         struct readline_type *readline)
 {
     w_queue_clear(word_chain);
     c_queue_clear(cmdlines);
-    dynarr_drop_word(tmp_word);
+    dynarr_reset_array(tmp_word);
+    readline_reset_array(readline);
     clear_filename(params);
     init_params(params, current_mode);
 }
@@ -126,11 +133,13 @@ void error_identification(const struct param_type *params)
 static int special_token_handling(struct w_queue *word_chain,
                                   struct c_queue *cmdlines,
                                   struct dynamic_array *tmp_word, int ch,
-                                  struct param_type *params)
+                                  struct param_type *params,
+                                  struct readline_type *readline)
 {
     return
-        stream_redirect_tokens(word_chain, tmp_word, ch, params) ?
-            1 : special_tokens(word_chain, cmdlines, tmp_word, ch, params);
+        stream_redirect_tokens(word_chain, tmp_word, ch, params, readline) ?
+            1 : special_tokens(word_chain, cmdlines, tmp_word, ch, params,
+                               readline);
 }
 
 static void wait_for_process_to_complete(struct p_queue *pid_store)
@@ -394,7 +403,7 @@ void add_filename(struct dynamic_array *tmp_word, struct param_type *params)
             malloc(tmp_word->last_element_index+1);
         dynarr_copy_array(tmp_word, params->streams.output_stream_to_append);
     }
-    dynarr_drop_word(tmp_word);
+    dynarr_reset_array(tmp_word);
     params->is_word = 0;
 }
 
@@ -405,7 +414,7 @@ void add_word(struct w_queue *word_chain, struct dynamic_array *tmp_word,
     char *word = malloc(tmp_word->last_element_index+1);
     dynarr_copy_array(tmp_word, word);
     w_queue_push(word_chain, word);
-    dynarr_drop_word(tmp_word);
+    dynarr_reset_array(tmp_word);
     params->is_word = 0;
 }
 
@@ -416,13 +425,86 @@ char** create_cmdline(const struct w_queue *word_chain, int word_counter)
     return cmdline;
 }
 
+static int readline_termination_condition(int ch,
+                                          struct readline_type *readline)
+{
+    return
+        ch == new_line ||
+            (ch == end_of_file && readline->last_element_index == -1);
+}
+
+static void echo_characters(int ch)
+{
+    write(1, &ch, 1);
+}
+
+static void generate_readline(struct readline_type *readline)
+{
+    enum keys found_key = none;
+    int match_result;
+    char ch;
+
+    while((ch = getchar()) && !readline_termination_condition(ch, readline)) {
+        if(ch == tab) {
+            if(suggestions_for_filename(readline)) {
+                match_result = get_filename_match(readline,
+                        get_start_filename_idx(readline));
+                if(!match_result)
+                    echo_characters(new_line);
+                show_invitation();
+                if(readline->last_element_index != -1)
+                    readline_print(readline);
+                /* program name is not empty */
+            } else if(readline->last_element_index != -1) {
+                match_result = get_program_name_match(readline);
+                if(!match_result)
+                    echo_characters(new_line);
+                show_invitation();
+                if(readline->last_element_index != -1)
+                    readline_print(readline);
+            }
+            continue;
+        }
+        if(ch == end_of_file)
+            continue;
+
+        /* moving */
+        found_key = readline_detect_arrow_keys(ch);
+        if(found_key != none && found_key != unknown_key) {
+            readline_move_along(readline, found_key);
+            continue;
+        }
+        if(found_key == unknown_key)
+            continue;
+
+        /* deletion */
+        if(ch == backspace) {
+            readline_character_deletion(readline);
+            continue;
+        }
+
+        echo_characters(ch);
+        readline_add_char(readline, ch);
+    }
+    /* moving cursor to end */
+    if(ch == new_line)
+        readline->cursor_pos = readline->last_element_index + 1;
+    /* adding '\n' to readline */
+    readline_add_char(readline, ch);
+    /* print '\n' to end of readline */
+    if(ch == new_line)
+        echo_characters(ch);
+}
+
 static void command_processing(struct param_type *params,
-                                enum modes *current_mode,
-                                struct w_queue *word_chain,
-                                struct c_queue *cmdlines,
-                                struct dynamic_array *tmp_word, int ch)
+                               enum modes *current_mode,
+                               struct w_queue *word_chain,
+                               struct c_queue *cmdlines,
+                               struct dynamic_array *tmp_word,
+                               struct readline_type *readline, int ch)
 {
     char **cmdline = NULL;
+    int last_token = 0;
 
     /* odd number of double quotes  */
     if(!is_double_quotes_pair(*params)) {
@@ -463,16 +545,22 @@ static void command_processing(struct param_type *params,
 
 clean:
     error_identification(params);
-    if(params->tokens == '&' || params->tokens == 0 || ch == new_line)
+    last_token = params->tokens;
+    reset_params(params, current_mode, word_chain, cmdlines, tmp_word,
+                 readline);
+
+    if(last_token == '&' || last_token == 0 || ch == new_line) {
         show_invitation();
-    reset_params(params, current_mode, word_chain, cmdlines, tmp_word);
+        generate_readline(readline);
+    }
 }
 
 static void word_separation_processing(int ch, struct param_type *params,
                                        enum modes *current_mode,
                                        struct w_queue *word_chain,
                                        struct c_queue *cmdlines,
-                                       struct dynamic_array *tmp_word)
+                                       struct dynamic_array *tmp_word,
+                                       struct readline_type *readline)
 {
     /* could be a marker for the beginning of a blank word */
     params->stored_symbol = ch;
@@ -492,16 +580,18 @@ static void word_separation_processing(int ch, struct param_type *params,
         params->escape_sequences = 1;
         return;
     }
-    if(special_token_handling(word_chain, cmdlines, tmp_word, ch, params)) {
+    if(special_token_handling(word_chain, cmdlines, tmp_word, ch, params,
+                              readline)) {
         if(command_execution_condition(params))
             command_processing(params, current_mode, word_chain, cmdlines,
-                               tmp_word, ch);
+                               tmp_word, readline, ch);
         return;
     }
     if(params->wrong_command) {
         error_identification(params);
         clean_input_buffer();
-        reset_params(params, current_mode, word_chain, cmdlines, tmp_word);
+        reset_params(params, current_mode, word_chain, cmdlines, tmp_word,
+                     readline);
         show_invitation();
         return;
     }
@@ -509,7 +599,8 @@ static void word_separation_processing(int ch, struct param_type *params,
         if(excessive_words(ch, params)) {
             error_identification(params);
             clean_input_buffer();
-            reset_params(params, current_mode, word_chain, cmdlines, tmp_word);
+            reset_params(params, current_mode, word_chain, cmdlines, tmp_word,
+                         readline);
             show_invitation();
             return;
         }
@@ -560,33 +651,69 @@ static void whole_word_processing(int ch, struct param_type *params,
     add_letter(ch, tmp_word, params);
 }
 
+static void change_terminal_settings(struct termios *cur_terminal_settings,
+                                     struct termios *save_terminal_settings)
+{
+    tcgetattr(0, save_terminal_settings);
+    memcpy(cur_terminal_settings, save_terminal_settings,
+           sizeof(*save_terminal_settings));
+    cur_terminal_settings->c_lflag &= ~(ICANON | ECHO);
+    tcsetattr(0, TCSANOW, cur_terminal_settings);
+}
+
+static void restore_terminal_settings(struct termios *cur_terminal_settings,
+                                      struct termios *save_terminal_settings)
+{
+    tcsetattr(0, TCSANOW, save_terminal_settings);
+}
+
 int main()
 {
-    int ch;
+    char ch;
+    int i;
     struct param_type params;
+    struct termios cur_terminal_settings, save_terminal_settings;
     struct w_queue word_chain;
     struct c_queue cmdlines;
     struct dynamic_array tmp_word;
+    struct readline_type readline;
     enum modes current_mode = word_separation;
 
+    change_terminal_settings(&cur_terminal_settings, &save_terminal_settings);
     w_queue_init(&word_chain);
     c_queue_init(&cmdlines);
     dynarr_create_array(&tmp_word);
+    readline_create_array(&readline);
     init_params(&params, &current_mode);
     show_invitation();
+    generate_readline(&readline);
+
+    for(i = 0; readline.arr[i] != end_of_file; ) {
+        ch = readline.arr[i];
+        readline.considered_index = i;
+
+        if(params.new_readline)
+            params.new_readline = 0;
 
-    while((ch = getchar()) != EOF) {
         if(ch == new_line)
             command_processing(&params, &current_mode, &word_chain,
-                               &cmdlines, &tmp_word, ch);
-        else if(current_mode == word_separation)
+                               &cmdlines, &tmp_word, &readline, ch);
+        else if(current_mode == word_separation) {
             word_separation_processing(ch, &params, &current_mode, &word_chain,
-                                       &cmdlines, &tmp_word);
+                                       &cmdlines, &tmp_word, &readline);
+            /* double token was found */
+            if(readline.considered_index != i)
+                ++i;
+         }
         else if(current_mode == whole_word)
             whole_word_processing(ch, &params, &current_mode, &word_chain,
                                   &tmp_word);
+        i = params.new_readline ? 0 : i + 1;
     }
+
+    restore_terminal_settings(&cur_terminal_settings, &save_terminal_settings);
     putchar(new_line);
     dynarr_clear(&tmp_word);
+    readline_clear(&readline);
     return 0;
 }