editor/editor.c

   1 #include "editor.h"
   2 #include <stdlib.h> // malloc(), free()
   3
   4 File *filebuffers = NULL;
   5 uint64_t numbuffers = 0;
   6
   7 // returns an index
   8 // we don't read 1 char at a time, because then we would have to either reallocate each line again for each character read or allocate a huge buffer
   9 int readfile(char *fn) {
  10         filebuffers = malloc(sizeof(File) * 5);
  11         File tmp;
  12         uint64_t numlines = 0, linechars = 0, filechars, i, index; // Unfortunately, this does not work on files of more than 18446744073709551616 bytes
  13         int64_t line = 0;
  14         uint32_t *linelengths;
  15         uint32_t linelength;
  16         char *buf;
  17         char ch;
  18
  19         tmp.fn = fn;
  20         tmp.fp = fopen(tmp.fn, "r");
  21
  22         if (tmp.fp == NULL) {
  23                 fclose(tmp.fp);
  24                 return -1;
  25         }
  26
  27         // definitely open
  28
  29         // Credit to http://stackoverflow.com/a/3464656
  30         fseek(tmp.fp, 0, SEEK_END);
  31         filechars = ftell(tmp.fp);
  32         rewind(tmp.fp);
  33
  34         buf = malloc(sizeof(char) * filechars);
  35
  36         fread(buf, sizeof(char), filechars, tmp.fp);
  37
  38         // count the newlines
  39         for (i = 0; i < filechars; ch = buf[i++]) {
  40                 if (ch == '\n') {
  41                         numlines++;
  42                 }
  43         }
  44         tmp.text = malloc(sizeof(char*) * numlines);
  45         linelengths = malloc(sizeof(uint64_t) * numlines);
  46
  47         tmp.numlines = numlines;
  48
  49         // count the number of chars in each line
  50         for (i = 0; i < filechars; ch = buf[i++]) {
  51                 if (ch == '\n') {
  52                         linelengths[line] = linelength;
  53                         linelength = 0;
  54                         line++;
  55                 } else {
  56                         linelength++;
  57                 }
  58         }
  59
  60         for (i = 0; i < numlines+1; i++) {
  61                 tmp.text[i] = malloc(sizeof(char) * (linelengths[1] + 2));
  62         }
  63
  64         line = -1;
  65
  66         // actually read the lines out
  67         for (i = 0; i < filechars; ch = buf[i++]) {
  68                 if (ch == '\n') {
  69                         (tmp.text[line])[index] = '\0';
  70                         index = 0;
  71                         line++;
  72                 } else {
  73                         (tmp.text[line])[index] = ch;
  74                         index++;
  75                 }
  76
  77         }
  78 }
  79
  80 void closebuffer(int index) {
  81         if ((index >= numbuffers) || (numbuffers == 0)) {
  82                 return;
  83         }
  84
  85         if (!(filebuffers[index].isclosed)) {
  86                 fclose(filebuffers[index].fp);
  87         }
  88
  89         File *files = malloc(sizeof(File)*(numbuffers-1));
  90
  91         if (index != 0) {for (int i=0; i < index; i++) {
  92                 files[i] = filebuffers[i];
  93         }}
  94
  95         if (index != numbuffers-1) { for (int i=index+1; i < numbuffers-1; i++) {
  96                 files[i-1] = filebuffers[i];
  97         }}
  98
  99         free(filebuffers);
 100         filebuffers = files;
 101         numbuffers--;
 102 }
 103
 104
 105 void closeallbuffers() {
 106         while (numbuffers) {
 107                 closebuffer(0);
 108         }
 109 }