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, 258 insertions, 0 deletions

diff --git a/file_suggestions.c b/file_suggestions.c
new file mode 100644
index 0000000..528d717
--- /dev/null
+++ b/file_suggestions.c
@@ -0,0 +1,258 @@
+#include "file_suggestions.h"
+#include "readline.h"
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <string.h>
+
+extern char **environ;
+
+static void clean_name_and_path(char *name, char *path)
+{
+    if(name)
+        free(name);
+    if(strcmp(path, "."))
+        free(path);
+}
+
+static int print_all_filenames(const char *name, const char *path)
+{
+    DIR *dir;
+    struct dirent *dent;
+    char *next_filename;
+    int first_suggestion;
+
+    first_suggestion = 1;
+
+    dir = opendir(path);
+    if(!dir) {
+        perror(path);
+        return 0;
+    }
+    while((dent = readdir(dir)) != NULL) {
+        next_filename = dent->d_name;
+        if(first_suggestion) {
+            putchar('\n');
+            first_suggestion = 0;
+        }
+        printf("%s\n", next_filename);
+    }
+    closedir(dir);
+    return 1;
+}
+
+static int matchmaking(const char *name, const char *path)
+{
+    DIR *dir;
+    struct dirent *dent;
+    char *next_filename;
+    int mismatch_status, first_suggestion, something_found;
+
+    mismatch_status = 0;
+    something_found = 0;
+    first_suggestion = 1;
+
+    dir = opendir(path);
+    if(!dir) {
+        perror(path);
+        return 0;
+    }
+    while((dent = readdir(dir)) != NULL) {
+        next_filename = dent->d_name;
+        int i;
+        for(i = 0; name[i] && next_filename[i]; ++i) {
+            if(name[i] != next_filename[i]) {
+                mismatch_status = 1;
+                break;
+            }
+        }
+        if(!mismatch_status && name[i] == '\0') {
+            if(first_suggestion) {
+                putchar('\n');
+                first_suggestion = 0;
+            }
+            printf("%s\n", next_filename);
+            if(!something_found)
+                something_found = 1;
+        }
+        mismatch_status = 0;
+    }
+    closedir(dir);
+    return something_found;
+}
+
+static void extract_path_and_name(char **path, char **name,
+                                  struct readline_type *readline,
+                                  int start_filename_idx)
+{
+    int i, j, k;
+
+    for(i = readline->last_element_index; i >= start_filename_idx; --i) {
+        if(readline->arr[i] == '/')
+            break;
+    }
+    *path = malloc(i - start_filename_idx+ 2);
+    *name = malloc(readline->last_element_index - i + 1);
+
+    /* extract path */
+    for(j = start_filename_idx, k = 0; j <= i; ++j, ++k)
+        (*path)[k] = readline->arr[j];
+    (*path)[k] = '\0';
+
+    /* extract name */
+    for(j = i + 1, k = 0; j <= readline->last_element_index; ++j, ++k)
+        (*name)[k] = readline->arr[j];
+    (*name)[k] = '\0';
+}
+
+static void copy_filename(char *dest, char *source, int start_idx, int last_idx)
+{
+    int i, j;
+    for(i = 0, j = start_idx; j <= last_idx; ++i, ++j)
+        dest[i] = source[j];
+}
+
+static void extract_only_filename(char **name, struct readline_type *readline,
+                                  int start_filename_idx)
+{
+    int size = readline->last_element_index - start_filename_idx + 2;
+    *name = malloc(size);
+    copy_filename(*name, readline->arr, start_filename_idx,
+                  readline->last_element_index);
+    (*name)[size-1] = '\0';
+}
+
+int get_filename_match(struct readline_type *readline, int start_filename_idx)
+{
+    int extract_path_status, match_result;
+
+    char *name = NULL;
+    extract_path_status = 0;
+    match_result = 0;
+    /* default path */
+    char *path = ".";
+    int i;
+
+    for(i = start_filename_idx; i <= readline->last_element_index; ++i) {
+        if(readline->arr[i] == '/') {
+            extract_path_status = 1;
+            break;
+        }
+    }
+    /* not empty filename */
+    if(readline->arr[start_filename_idx] != ' ')
+        extract_path_status ? extract_path_and_name(&path, &name, readline,
+                                                    start_filename_idx) :
+                                extract_only_filename(&name, readline,
+                                                      start_filename_idx);
+    match_result =
+        (name == NULL && !strcmp(path, ".")) ? print_all_filenames(name, path) :
+                                                        matchmaking(name, path);
+    clean_name_and_path(name, path);
+    return match_result;
+}
+
+static int is_token(int ch)
+{
+    return ch == ' ' || ch == '|' || ch == '&' || ch == ';' || ch == '<' ||
+            ch == '>';
+}
+
+int get_start_filename_idx(struct readline_type *readline)
+{
+    /* empty filename */
+    if(readline->last_element_index == ' ')
+        return readline->last_element_index;
+
+    int i;
+    for(i = readline->last_element_index; i != -1; --i) {
+        if(is_token(readline->arr[i]))
+            return ++i;
+    }
+    return 0;
+}
+
+/*
+ * 1 searching for suggestions for file name,
+ * 0 searching for program name from PATH
+ */
+int suggestions_for_filename(struct readline_type *readline)
+{
+    int token_status, i;
+    token_status = 0;
+
+    for(i = readline->last_element_index; i != -1; --i) {
+        if(is_token(readline->arr[i])) {
+            token_status = 1;
+            continue;
+        }
+        if(token_status && !is_token(readline->arr[i]))
+            return 1;
+    }
+    return 0;
+}
+
+int find_separator_index(char *path, int begin_idx)
+{
+    int i;
+    for(i = begin_idx; path[i] != ':' && path[i]; ++i)
+    {}
+    return i;
+}
+
+int get_program_name_match(struct readline_type *readline)
+{
+    char *name = NULL;
+    char *path = NULL;
+    char *path_variable = NULL;
+    int size, begin_idx, end_idx, result;
+
+    begin_idx = 0;
+    end_idx = 0;
+    result = 0;
+    size = readline->last_element_index + 2;
+    name = malloc(size);
+
+    /* extracting prog name */
+    int i;
+    for(i = 0; i <= readline->last_element_index; ++i)
+        name[i] = readline->arr[i];
+    name[i] = '\0';
+
+    /* searching PATH */
+    for(i = 0; environ[i]; ++i)
+        if(!strncmp(environ[i], "PATH", 4)) {
+            path_variable = environ[i];
+            break;
+        }
+    if(!path_variable)
+        return 0;
+
+    /* skipping PATH= */
+    path_variable = path_variable + 5;
+
+    /* directory search by separator (:) */
+    end_idx = find_separator_index(path_variable, begin_idx);
+    size = end_idx + 1;
+    path = malloc(size);
+    copy_filename(path, path_variable, begin_idx, end_idx - 1);
+    path[end_idx] = '\0';
+    result = matchmaking(name, path) ? 1 : result;
+    free(path);
+
+    /* if end_idx is beginning with ':' */
+    while(path_variable[end_idx]) {
+        begin_idx = end_idx + 1;
+        end_idx = find_separator_index(path_variable, begin_idx);
+        size = end_idx + 1;
+        path = malloc(size);
+        copy_filename(path, path_variable, begin_idx, end_idx - 1);
+        path[end_idx] = '\0';
+        result = matchmaking(name, path) ? 1 : result;
+        free(path);
+    }
+    free(name);
+    return result;
+}