finish ed

3 files changed, 254 insertions, 23 deletions

diff --git a/readme.md b/readme.md
index 8308f19..2c02009 100644
--- a/readme.md
+++ b/readme.md
@@ -4,7 +4,7 @@
 A terrible busybox/gnu coreutils clone.
 
 Currently the only supported commands are: 
-`dd`, `cat`, `yes`, `echo`, `printf`, `id`, `groups`, `ls`, `tail`, `head`
+`dd`, `cat`, `yes`, `echo`, `printf`, `id`, `groups`, `ls`, `tail`, `head`, `ed`
  
 ## How to
 
diff --git a/src/commands/ed.c b/src/commands/ed.c
index 2082ef6..7c55ce0 100644
--- a/src/commands/ed.c
+++ b/src/commands/ed.c
@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 #define INPUT_LEN 1024
 
@@ -12,11 +13,14 @@ static unsigned long line_capacity;
 static unsigned long line_count;
 static unsigned long line_current;
 static bool pending_writes;
+static char* default_filename = NULL;
+static re_t last_regex = NULL;
 
 enum LineAddressType {
     INDEX,
     RANGE,
     SET,
+    FREE
 };
 
 struct LineAddress {
@@ -64,6 +68,8 @@ static bool parse_regex(char** end, struct LineAddress* address, enum RegexDirec
     long int* buf = malloc(cap * sizeof(unsigned long));
 
     re_t regex = re_compile(regex_str);
+    last_regex = regex;
+
     unsigned long i = (dir == ALL ? 0 : line_current);
     unsigned long until = (dir == BEFORE ? 0 : line_count - 1);
     for (; (dir == BEFORE ? i >= until : i < until); dir == BEFORE ? i-- : i++) {
@@ -81,6 +87,7 @@ static bool parse_regex(char** end, struct LineAddress* address, enum RegexDirec
         if (dir == BEFORE && i == 0) break;
     }
 
+    address->empty = false;
     address->type = SET;
     address->data.set.s = siz;
     address->data.set.c = cap;
@@ -207,19 +214,26 @@ static bool read_address(char** command, bool whitespace, struct LineAddress* a)
 
 static void free_address (struct LineAddress address) {
     if (address.type != SET) return;
+    address.type = FREE;
     free(address.data.set.b);
 }
 
-static void free_data() {
-    if (lines == NULL) return;
-    for (unsigned long i = 0; i < line_count; i++) 
-        free(lines[i]);
-    free(lines);
-    lines = NULL;
+static void free_data(bool all) {
+    if (lines != NULL) {
+        for (unsigned long i = 0; i < line_count; i++) {
+            free(lines[i]);
+        }
+        free(lines);
+        lines = NULL;
+    }
+    if (all && default_filename != NULL) {
+        free(default_filename);
+        default_filename = NULL;
+    }
 }
 
 static void load_empty() {
-    free_data();
+    free_data(false);
 
     line_capacity = 8;
     lines = malloc(sizeof(char*) * line_capacity);
@@ -275,19 +289,20 @@ int ed_getline(char *buf, size_t size) {
 }
 
 static void load_file(FILE* file) {
-    free_data();
+    free_data(false);
     line_current = 0;
     get_input(file, &lines, &line_capacity, &line_count);
     if (file != stdin)
         fclose(file);
+    
 }
 
-static bool check_if_sure() {
+static bool check_if_sure(char* prompt) {
     if (!pending_writes) {
         return true;
     }
 
-    printf("Do you really want to quit? ");
+    printf("%s", prompt);
     fflush(stdout);
 
     char buf[INPUT_LEN];
@@ -352,6 +367,7 @@ static bool handle_append(struct LineAddress* address) {
     get_input(stdin, &buf, &cap, &size);
     if (size > 0) {
         append_lines(address->data.index.i + 1, buf, size);
+        printf("ed: appened %lu lines\n", size);
     }
     line_current += size;
     free(buf);
@@ -365,18 +381,143 @@ static bool handle_delete(struct LineAddress* address) {
     }
     if (address->type == INDEX) {
         delete_lines(address->data.index.i, address->data.index.i);
+        printf("ed: deleted line %ld\n", address->data.index.i+1);
     } else if (address->type == RANGE) {
         delete_lines(address->data.range.a, address->data.range.b);
+        printf("ed: deleted lines %ld-%ld\n", address->data.range.a+1, address->data.range.b+1);
     } else if (address->type == SET) {
         for (unsigned long i = 0; i < address->data.set.s; i++) {
             delete_lines(address->data.set.b[i], address->data.set.b[i]);
         }
+        printf("ed: deleted %lu lines\n", address->data.set.s);
+    }
+    return true;
+}
+
+static bool get_file_name(char** filename) {
+    size_t len = strlen(*filename);
+    if (len < 1 || (len == 1 && **filename == '\n')) {
+        if (default_filename == NULL) {
+            fprintf(stderr, "error: no default filename specified\n");
+            return false;
+        }
+        *filename = default_filename;
+    } else {
+        if ((*filename)[len - 1] == '\n') {
+            (*filename)[len - 1] = '\0';
+            len--;
+        }
+        if (default_filename != NULL) {
+            default_filename = realloc(default_filename, len + 1);
+        } else {
+            default_filename = malloc(len + 1);
+        }
+        memcpy(default_filename, *filename, len + 1);
+        *filename = default_filename;
     }
     return true;
 }
 
+static void write_file(char* filename, struct LineAddress* address, char* type) {
+    if (line_count < 1) {
+        fprintf(stderr, "error: cannot write empty file\n");
+        return;
+    }
+    if (!get_file_name(&filename)) return;
+    FILE* file = get_file_s(filename, type);
+    if (file == NULL) return;
+    int wrote = 0;
+    if (address->empty) {
+        for (unsigned long i = 0; i < line_count; i++) {
+            fprintf(file, "%s", lines[i]); 
+            wrote++;
+        }
+    } else if (address->type == INDEX) {
+        long int i = address->data.index.i;
+        fprintf(file, "%s", lines[i]); 
+        wrote++;
+    } else if (address->type == RANGE) {
+        for (long int i = address->data.range.a; i < address->data.range.b; i++) {
+            fprintf(file, "%s", lines[i]); 
+            wrote++;
+        }
+    } else if (address->type == SET) {
+        for (unsigned long i = 0; i < address->data.set.s; i++) {
+            fprintf(file, "%s", lines[address->data.set.b[i]]);
+            wrote++;
+        }
+    }
+    pending_writes = false;
+    fclose(file);
+    printf("ed: wrote %d lines from %s\n", wrote, filename);
+}
+
+static void read_file(char* filename) {
+    if (!get_file_name(&filename)) return;
+    FILE* file = get_file_s(filename, "r");
+    if (file == NULL) return;
+
+    unsigned long capacty = 8;
+    unsigned long size = 0;
+    char** buf = malloc(capacty * sizeof(char*));
+    get_input(file, &buf, &capacty, &size);
+
+    if (size < 1) {
+        free(buf);
+        fprintf(stderr, "error: attempted to read a empty file\n");
+        return;
+    }
+
+    long int line = -1;
+    if (line_count > 0) {
+        line = line_count - 1;
+    }
+    append_lines(line, buf, size);
+    free(buf);
+    printf("ed: read and appended %lu lines from %s\n", size, filename);
+}
+
+static void expand_string(char** buf, int* capacity, int* size, char* text, int len) {
+    if (*size + len >= *capacity) {
+        *capacity *= 2;
+        if (*capacity < *size + len) *capacity = *size + len;
+        *buf = realloc(*buf, *capacity);
+    }
+    memcpy(*buf + *size, text, len);
+    *size += len;
+}
+
+static int substute_string(long int index, long int matches, re_t regex, char* sub, int sub_len) {
+    int capacity = 8;
+    int size = 0;
+    char* buf = malloc(sizeof(char) * capacity);
+
+    int offset = 0;
+    int matches_found = 0;
+    while(true) {
+        if (lines[index][offset] == '\0') break;
+        if (matches_found >= matches && matches > 0) break;
+        int distance, len;
+        if ((distance = re_matchp(regex, &lines[index][offset], &len)) == -1) {
+            break;
+        }
+        if (distance > 0)
+            expand_string(&buf, &capacity, &size, &lines[index][offset], distance);
+        expand_string(&buf, &capacity, &size, sub, sub_len);
+        offset += len + distance;
+        matches_found++;
+    }
+
+    long int left = strlen(lines[index] + offset);
+    expand_string(&buf, &capacity, &size, &lines[index][offset], left + 1);
+
+    free(lines[index]);
+    lines[index] = buf;
+    return matches_found;
+}
+
 static void prompt() {
-    printf("%ld: ", line_current + 1);
+    printf(": ");
     fflush(stdout);
 
     char buf[INPUT_LEN];
@@ -422,9 +563,11 @@ static void prompt() {
         return;
     }
 
+    bool linenumbers = false;
+test:
     switch (cmd) {
-        case '\n':
         case '\0':
+        case '\n':
             if (address.empty) {
                 if (line_current == line_count) {
                     fprintf(stderr, "error: line number %ld does not exist\n", line_current + 1);
@@ -460,46 +603,133 @@ static void prompt() {
             address.data.index.i = line_current - 1;
             handle_append(&address);
             break;
+        case 'n':
+            linenumbers = true;
+            __attribute__((fallthrough));
         case 'p':
             if (address.empty && address.data.index.i >= (long int) line_count) {
                 fprintf(stderr, "error: line number %ld does not exist\n", address.data.index.i + 1);
                 break;
             }
             if (address.type == INDEX) {
+                if (linenumbers) printf("%ld\t", address.data.index.i + 1);
                 printf("%s", lines[address.data.index.i]);
             } else if (address.type == RANGE) {
                 for (long int i = address.data.range.a; i <= address.data.range.b; i++) {
+                    if (linenumbers) printf("%ld\t", i + 1);
                     printf("%s", lines[i]);
                 }
             } else if (address.type == SET) {
                 for (unsigned long i = 0; i < address.data.set.s; i++) {
+                    if (linenumbers) printf("%ld\t", i +1);
                     printf("%s", lines[address.data.set.b[i]]);
                 }
             }
             break;
         case 'q':
-            if(check_if_sure()) {
-                free_address(address);
-                free_data();
-                exit(EXIT_SUCCESS);
-            };
-            break;
+            if (!check_if_sure("Quit for sure? ")) break;
+            __attribute__((fallthrough));
         case 'Q':
             free_address(address);
-            free_data();
+            free_data(true);
             exit(EXIT_SUCCESS);
+            break;
         case 'g':
             skip_whitespace(&index);
             free_address(address);
             if (*(index++) != '/') {
-                fprintf(stderr, "error: unexpected character at start or regex\n");
+                fprintf(stderr, "error: unexpected character at start of regex\n");
+                break;
+            }
+            if (!parse_regex(&index, &address, ALL)) { return; }
+            skip_whitespace(&index);
+            if (*index == '\n' || *index == '\0') {
+                cmd = 'p';
+            } else {
+                cmd = *(index++);
+            }
+            goto test;
+            break;
+        case 's':
+            skip_whitespace(&index);
+            free_address(address);
+            if (*(index++) != '/') {
+                fprintf(stderr, "error: unexpected character at start of regex\n");
                 break;
             }
             if (!parse_regex(&index, &address, ALL)) { return; }
+            char* replace = index;
+            while(*index != '\0' && *index != '/') index++;
+            if (*index != '/') {
+                fprintf(stderr, "error: / missing after %c\n", *index);
+                break;
+            }
+            if (address.data.set.s < 1) {
+                printf("ed: no matches found\n");
+                break;
+            }
+            *(index++) = '\0';
+            long int matches;
+            if (*index == '\0') {
+                matches = 1;
+            } else if (*index == 'g') {
+                matches = -1;
+            } else {
+                char* end;
+                matches = strtol(index, &end, 10);
+                if (end == index) {
+                    fprintf(stderr, "error: invalid number: %s\n", index);
+                    break;
+                }
+            }
+            long int sub_len = strlen(replace);
+            long int matches_found = 0;
+            
             for (unsigned long i = 0; i < address.data.set.s; i++) {
-                printf("%s", lines[address.data.set.b[i]]);
+                matches_found += substute_string(address.data.set.b[i], matches, last_regex, replace, sub_len);
+            }
+            printf("ed: replaced %ld matches over %ld lines\n", matches_found, address.data.set.s);
+            pending_writes = true;
+            break;
+        case 'w': {
+            bool quit = false;
+            if (*index == 'q') {
+                index++;
+                quit = true;
+            }
+            skip_whitespace(&index);
+            write_file(index, &address, "w");
+            if (quit) {
+                free_address(address);
+                free_data(true);
+                exit(EXIT_SUCCESS);
             }
             break;
+        }
+        case 'r': {
+            skip_whitespace(&index);
+            read_file(index);
+            break;
+        }
+        case 'e': 
+            if (!check_if_sure("Load new file for sure? ")) break;
+            __attribute__((fallthrough));
+        case 'E': {
+            skip_whitespace(&index);
+            char* filename = index;
+            if(!get_file_name(&filename)) break;
+            FILE* file = get_file_s(filename, "r");
+            if (file == NULL) break;
+            load_file(file);
+            break;
+        }
+        case 'W':
+            skip_whitespace(&index);
+            write_file(index, &address, "a");
+            break;
+        case '=':
+            printf("%ld\n", line_current + 1);
+            break;
         default:
             fprintf(stderr, "error: unimplemented command\n");
             break;
@@ -522,6 +752,7 @@ COMMAND(ed) {
     } else {
         FILE* file = get_file(argv[0], "r");
         load_file(file);
+        get_file_name(&argv[0]);
         prompt_loop();
     }
     return EXIT_SUCCESS;
diff --git a/src/util/shared.c b/src/util/shared.c
index c5c22e9..d512972 100644
--- a/src/util/shared.c
+++ b/src/util/shared.c
@@ -32,7 +32,7 @@ FILE* get_file_s(const char* path, const char* type) {
 read:
     file = fopen(path, type);
     if (file == NULL) {
-        fprintf(stderr, "error: failed to open file %s: %s\n", path, strerror(errno));
+        fprintf(stderr, "error: failed to %s file %s: %s\n", type[0] == 'r' ? "read" : "write", path, strerror(errno));
     }
     return file;
 }