Справочник по консольным командам Toybox для Android 12


  Ver.0.8.4     Ver.0.8.9     Pending  

Путь: Toys/Pending, команды версии: Ver.4     Ver.9


diff

Комментарии в файле diff.c :

usage: diff [-abBdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] [-F REGEX ] FILE1 FILE2

  • -a Обрабатывать все файлы как текст
  • -b Игнорировать изменения в количестве пробелов
  • -B Игнорировать изменения, все строки которых
  • -d пусты Стараться найти меньший набор изменений
  • -F Показать самую последнюю строку, соответствующую регулярному выражению
  • -i Игнорировать различия в регистре -L Использовать LABEL вместо имени файла в унифицированном заголовке
  • -N Обработать отсутствующие файлы как пустые
  • -q Вывод только того, различаются ли файлы
  • -r Рекурсивно
  • -S начинать с ФАЙЛА при сравнении каталогов
  • -s Сообщать, когда два файла одинаковы
  • -T Выравнивать вкладки, добавляя префикс табуляции, когда это необходимо
  • -t Расширять вкладки до пробелов в выводе
  • -u Унифицированный diff
  • -U Выводить СТРОКИ контекста
  • -w Игнорировать все пробелы
  • --color Цвет output --strip-trailing-cr Удалить '\r' из входных строк
  • --TYPE-line-format=FORMAT Показать строки TYPE (неизмененные/старые/новые) с помощью FORMAT ФОРМАТ использует экранирование целого числа printf (например, %-2.4x), за которым следует ПИСЬМО: FELMNn Поддерживаемые спецификаторы формата:

  • usage: diff [-abBdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] [-F REGEX ] FILE1 FILE2

  • -a Treat all files as text
  • -b Ignore changes in the amount of whitespace
  • -B Ignore changes whose lines are all blank
  • -d Try hard to find a smaller set of changes
  • -F Show the most recent line matching the regex
  • -i Ignore case differences
  • -L Use LABEL instead of the filename in the unified header
  • -N Treat absent files as empty
  • -q Output only whether files differ
  • -r Recurse
  • -S Start with FILE when comparing directories
  • -s Report when two files are the same
  • -T Make tabs line up by prefixing a tab when necessary
  • -t Expand tabs to spaces in output
  • -u Unified diff
  • -U Output LINES lines of context
  • -w Ignore all whitespace
  • --color Color output --strip-trailing-cr Strip '\r' from input lines
  • --TYPE-line-format=FORMAT Display TYPE (unchanged/old/new) lines using FORMAT FORMAT uses printf integer escapes (ala %-2.4x) followed by LETTER: FELMNn Supported format specifiers are:

  • Исходный текст в файле diff.c

    #define FOR_diff
    #include "toys.h"
    
    GLOBALS(
      long U;
      struct arg_list *L;
      char *F, *S, *new_line_format, *old_line_format, *unchanged_line_format;
    
      int dir_num, size, is_binary, differ, change, len[2], *offset[2];
      struct stat st[2];
      struct {
        char **list;
        int nr_elm;
      } dir[2];
      struct {
        FILE *fp;
        int len;
      } file[2];
    )
    
    #define IS_STDIN(s)     (*(s)=='-' && !(s)[1])
    
    struct v_vector {
      unsigned serial:31;
      unsigned last:1;
      union {
        unsigned hash;
        unsigned p;
      };
    };
    
    struct diff {
      long a, b, c, d, prev, suff;
    };
    
    struct candidate {
      struct candidate *next, *prev;
      int a, b;
    };
    
    enum {
      empty = 1 << 9,
      eol = 1 << 10,
      eof = 1 << 11,
      space = 1 << 12
    };
    
    static int comp(void *a, void *b)
    {
      int i = ((struct v_vector *)a)->hash - ((struct v_vector *)b)->hash;
    
      return i ? : ((struct v_vector *)a)->serial - ((struct v_vector *)b)->serial;
    }
    
    static int search(struct candidate **K, int r, int k, int j)
    {
      int low = r, upper = k, mid;
    
      while (low<=(mid = (low+upper)/2)) {
        if (K[mid]->b < j && K[mid + 1]->b > j) return mid;
        if (K[mid]->b < j) low = mid + 1;
        else if (K[mid]->b > j) upper = mid - 1;
        else return -1;
      }
      return -1;
    }
    
    static struct candidate *new_candidate(int i, int j, struct candidate *prev)
    {
      struct candidate *c = xzalloc(sizeof(struct candidate));
    
      c->a = i;
      c->b = j;
      c->prev = prev;
      return c;
    }
    
    /* 1. Search K[r: k] for an element K[s] such that K[s]-> b < j and K[s + 1]->b > j
     * 2. if found do
     *  2.a. If K[s + 1]->b > j do K[r] = c; r = s+1 and c = candidate(i, j, K[s]) //we have a candidate
     *  2.b. if s = k (fence reached move it further) do K[k + 2] = K[k + 1], k++
     * 3. if E[p].last true break i.e we have reached at the end of an equiv class
     *    else p = p + 1 //keep traversing the equiv class.
     * 4. K[r] = c //Save the sucessfully filled k-candidate.
     */
    static void do_merge(struct candidate **K, int *k, int i,
        struct v_vector *E, int p)
    {
      int r = 0, s, j;
      struct candidate *pr = 0, *c = K[0];
    
      for (;;) {
        j = E[p].serial;
        s = search(K, r, *k, j);
        if (s>=0 && K[s]->b<j && K[s+1]->b>j) {
          if (K[s+1]->b>j) {
            pr = K[s];
            if (r && K[r]) c->next = K[r];
            K[r] = c;
            r = s+1;
            c = new_candidate(i , j, pr);
          }
          if (s == *k) {
            ++*k;
            K[*k+1] = K[*k];
            break;
          }
        }
        if (E[p].last) break;
        else p++;
      }
      K[r] = c;
    }
    
    static int read_tok(FILE *fp, off_t *off, int tok)
    {
      int t = 0, is_space;
    
      tok |= empty;
      while (!(tok & eol)) {
        t = fgetc(fp);
    
        if (FLAG(strip_trailing_cr) && t == '\r') {
          int t2 = fgetc(fp);
          if (t2 == '\n') {
            t = t2;
            if (off) (*off)++;
          } else {
            ungetc(t2, fp);
          }
        }
    
        if (off && t != EOF) *off += 1;
        is_space = isspace(t) || (t == EOF);
        tok |= (t & (eof + eol)); //set tok eof+eol when t is eof
    
        if (t == '\n') tok |= eol;
        if (FLAG(i)) if (t >= 'A' && t <= 'Z') t = tolower(t);
    
        if (FLAG(w) && is_space) continue;
    
        if (FLAG(b)) {
          if (tok & space) {
            if (is_space) continue;
            tok &= ~space;
          } else if (is_space) t = space + ' ';
        }
        tok &= ~(empty + 0xff);  //remove empty and char too.
        tok |= t; //add most recent char
        break;
      }
    
      return tok;
    }
    
    int bcomp(void *a, void *b)
    {
      struct v_vector *l = (struct v_vector *)a, *r = (struct v_vector *)b;
    
      return (l->hash-r->hash) ? : r[-1].last ? 0 : -1;
    }
    
    /*  file[0] corresponds file 1 and file[1] correspond file 2.
     * 1. calc hashes for both the files and store them in vector(v[0], v[1])
     * 2. sort file[1] with hash as primary and serial as sec. key
     * 3. Form the equivalance class of file[1] stored in e vector. It lists all the equivalence
     *    classes of lines in file[1], with e.last = true on the last element of each class.
     *    The elements are ordered by serial within classes.
     * 4. Form the p vector stored in  p_vector. p_vector[i], if non-zero, now points in e vector
     *    to the beginning of the equiv class of lines in file[1] equivalent to line
     *    i in file[0].
     * 5. Form the k-candidates as discribed in do_merge.
     * 6. Create a vector J[i] = j, such that i'th line in file[0] is j'th line of
     *    file[1], i.e J comprises LCS
     */
    static int *create_j_vector()
    {
      int tok, i, j, size = 100, k;
      off_t off;
      long hash;
      int *p_vector, *J;
      struct v_vector *v[2], *e;
      struct candidate **kcand, *pr;
    
      for (i = 0; i < 2; i++) {
        tok = off = 0;
        hash = 5831;
        v[i] = xzalloc(size * sizeof(struct v_vector));
        TT.offset[i] = xzalloc(size * sizeof(int));
        TT.file[i].len = 0;
        if (fseek(TT.file[i].fp, 0, SEEK_SET)) perror_exit("fseek failed");
    
        while (1) {
          tok  = read_tok(TT.file[i].fp, &off, tok);
          if (!(tok & empty)) {
            hash = ((hash << 5) + hash) + (tok & 0xff);
            continue;
          }
    
          if (size == ++TT.file[i].len) {
            size = size * 11 / 10;
            v[i] = xrealloc(v[i], size*sizeof(struct v_vector));
            TT.offset[i] = xrealloc(TT.offset[i], size*sizeof(int));
          }
    
          v[i][TT.file[i].len].hash = hash & INT_MAX;
          TT.offset[i][TT.file[i].len] = off;
          if ((tok & eof)) {
            TT.offset[i][TT.file[i].len] = ++off;
            break;
          }
          hash = 5831;  //next line
          tok = 0;
        }
        if (TT.offset[i][TT.file[i].len]-TT.offset[i][TT.file[i].len-1] == 1)
          TT.file[i].len--;
      }
    
      for (i = 0; i<=TT.file[1].len; i++) v[1][i].serial = i;
      qsort(v[1]+1, TT.file[1].len, sizeof(struct v_vector), (void *)comp);
    
      e = v[1];
      e[0].serial = 0;
      e[0].last = 1;
      for (i = 1; i<=TT.file[1].len; i++)
        e[i].last = i==TT.file[1].len || v[1][i].hash!=v[1][i+1].hash;
    
      p_vector = xzalloc((TT.file[0].len+2)*sizeof(int));
      for (i = 1; i<=TT.file[0].len; i++) {
        void *r = bsearch(&v[0][i], e+1, TT.file[1].len, sizeof(*e), (void *)bcomp);
        if (r) p_vector[i] = (struct v_vector *)r - e;
      }
    
      for (i = 1; i<=TT.file[0].len; i++) e[i].p = p_vector[i];
      free(p_vector);
    
      size = 100;
      kcand = xzalloc(size * sizeof(struct candidate *));
    
      kcand[0] = new_candidate(0 , 0, 0);
      kcand[1] = new_candidate(TT.file[0].len+1, TT.file[1].len+1, 0); //the fence
    
      k = 0;  //last successfully filled k candidate.
      for (i = 1; i<=TT.file[0].len; i++) {
        if (!e[i].p) continue;
        if ((size - 2) == k) {
          size = size * 11 / 10;
          kcand = xrealloc(kcand, (size*sizeof(struct candidate *)));
        }
        do_merge(kcand, &k, i, e, e[i].p);
      }
      free(v[0]); //no need for v_vector now.
      free(v[1]);
    
      J = xzalloc((TT.file[0].len+2)*sizeof(int));
    
      for (pr = kcand[k]; pr; pr = pr->prev) J[pr->a] = pr->b;
      J[TT.file[0].len+1] = TT.file[1].len+1; //mark boundary
    
      for (i = k+1; i>=0; i--) llist_traverse(kcand[i], free);
      free(kcand);
    
      for (i = 1; i<=TT.file[0].len; i++) { // jackpot?
        if (!J[i]) continue;
    
        if (fseek(TT.file[0].fp, TT.offset[0][i-1], SEEK_SET)
         || fseek(TT.file[1].fp, TT.offset[1][J[i]-1], SEEK_SET))
           perror_exit("fseek");
    
        for (j = J[i]; i<=TT.file[0].len && J[i]==j; i++, j++) {
          int tok0 = 0, tok1 = 0;
    
          do {
            tok0 = read_tok(TT.file[0].fp, NULL, tok0);
            tok1 = read_tok(TT.file[1].fp, NULL, tok1);
            if (((tok0 ^ tok1) & empty) || ((tok0 & 0xff) != (tok1 & 0xff)))
              J[i] = 0;
          } while (!(tok0 & tok1 & empty));
        }
      }
      return J;
    }
    
    static int *diff(char **files)
    {
      size_t i ,j;
      int s, t;
      char *bufi, *bufj;
    
      TT.is_binary = 0; //loop calls to diff
      TT.differ = 0;
    
      for (i = 0; i < 2; i++) {
        if ((j = !strcmp(files[i], "-")) || S_ISFIFO(TT.st[i].st_mode)) {
          char *tmp_name;
          int srcfd = j ? 0 : open(files[i], O_RDONLY),
            tmpfd = xtempfile("fifo", &tmp_name);
    
          unlink(tmp_name);
          free(tmp_name);
    
          xsendfile(srcfd, tmpfd);
          if (!j) close(srcfd);
          TT.file[i].fp = fdopen(tmpfd, "r");
        } else TT.file[i].fp = fopen(files[i], "r");
    
        if (!TT.file[i].fp) {
          perror_msg("%s", files[i]);
          TT.differ = 2;
          return 0; //return SAME
        }
      }
    
      s = sizeof(toybuf)/2;
      bufi = toybuf;
      bufj = toybuf+s;
    
      if (fseek(TT.file[0].fp, 0, SEEK_SET) || fseek(TT.file[1].fp, 0, SEEK_SET))
        perror_exit("fseek");
    
      if (FLAG(a)) return create_j_vector();
    
      while (1) {
        i = fread(bufi, 1, s, TT.file[0].fp);
        j = fread(bufj, 1, s, TT.file[1].fp);
    
        if (i != j) TT.differ = 1;
    
        for (t = 0; t < i && !TT.is_binary; t++) if (!bufi[t]) TT.is_binary = 1;
        for (t = 0; t < j && !TT.is_binary; t++) if (!bufj[t]) TT.is_binary = 1;
    
        i = minof(i, j);
        for (t = 0; t < i; t++) if (bufi[t] != bufj[t]) TT.differ = 1;
    
        if (!i || !j) break;
      }
      if (TT.is_binary || !TT.differ) return 0;
    
      return create_j_vector();
    }
    
    static void print_line_matching_regex(int a, regex_t *reg, int *off_set, FILE *fp) {
      int i = 0, j = 0, line_buf_size = 100, cc = 0;
      char* line = xzalloc(line_buf_size * sizeof(char));
      for (i = a; a > 0; --i) {
        int line_len = 0;
        if (fseek(fp, off_set[i - 1], SEEK_SET)) perror_exit("fseek failed");
        for (j = 0; j < (off_set[i] - off_set[i - 1]); j++) {
          cc = fgetc(fp);
          if (cc == EOF || cc == '\n') {
            break;
          }
          ++line_len;
          if (line_len >= line_buf_size) {
            line_buf_size = line_buf_size * 11 / 10;
            line = xrealloc(line, line_buf_size*sizeof(char));
          }
          line[j] = cc;
        }
        line[line_len] = '\0';
        if (!regexec0(reg, line, line_len, 0, NULL, 0)) {
          printf(" %s", line);
          break;
        }
      }
      free(line);
    }
    
    static void print_diff(int a, int b, char c, int *off_set, FILE *fp)
    {
      int i, j, cc, cl;
      char *reset = 0, *fmt = 0;
    
      if (!TT.new_line_format && c!=' ' && FLAG(color)) {
        printf("\e[%dm", 31+(c=='+'));
        reset = "\e[0m";
      }
    
      for (i = a; i <= b; i++) {
        if (fseek(fp, off_set[i - 1], SEEK_SET)) perror_exit("fseek failed");
        if (TT.new_line_format) {
          if (c == '+') fmt = TT.new_line_format;
          else if (c == '-') fmt = TT.old_line_format;
          else fmt = TT.unchanged_line_format;
          while (*fmt) {
            if (*fmt == '%') {
              fmt++;
              char f = *fmt++;
              if (f == '%') putchar('%');
              else if (f == 'l' || f == 'L') {
                for (j = 0; j <  (off_set[i] - off_set[i - 1]); j++) {
                  cc = fgetc(fp);
                  if (cc == EOF) break;
                  if (cc != '\n' || f == 'L') putchar(cc);
                }
              } else error_exit("Unrecognized format specifier %%%c", f);
            } else putchar(*fmt++);
          }
          continue;
        }
        putchar(c);
        if (FLAG(T)) putchar('\t');
        for (j = 0, cl = 0; j <  (off_set[i] - off_set[i - 1]); j++) {
          cc = fgetc(fp);
          if (cc == EOF) {
            printf("%s\n\\ No newline at end of file\n", reset ? : "");
            return;
          }
          if ((cc == '\t') && FLAG(t)) do putchar(' '); while (++cl & 7);
          else {
            putchar(cc); //xputc has calls to fflush, it hurts performance badly.
            cl++;
          }
        }
      }
      if (reset) xputsn(reset);
    }
    
    static char *concat_file_path(char *path, char *default_path)
    {
      char *final_path;
    
      if ('/' == path[strlen(path) - 1]) {
        while (*default_path == '/') ++default_path;
        final_path = xmprintf("%s%s", path, default_path);
      }
      else if (*default_path != '/')
        final_path = xmprintf("%s/%s", path, default_path);
      else final_path = xmprintf("%s%s", path, default_path);
      return final_path;
    }
    
    static int skip(struct dirtree *node)
    {
      int len = strlen(toys.optargs[TT.dir_num]), ret = 0;
      char *tmp = NULL, *ptr, *f_path = dirtree_path(node, NULL);
      struct stat st;
    
      ptr = f_path;
      ptr += len;
      if (ptr[0]) {
        tmp = concat_file_path(toys.optargs[1 - TT.dir_num], ptr);
        if (tmp && !stat(tmp, &st)) ret = 0; //it is there on other side
        else ret = 1; //not present on other side.
      }
      free(f_path);
      if (tmp) free(tmp);
      return ret; //add otherwise
    }
    
    static void add_to_list(struct dirtree *node)
    {
      char *full_path;
    
      TT.dir[TT.dir_num].list = xrealloc(TT.dir[TT.dir_num].list,
          (TT.size + 1)*sizeof(char*));
      TT.size++;
      full_path = dirtree_path(node, NULL);
      TT.dir[TT.dir_num].list[TT.size - 1] = full_path;
    }
    
    static int list_dir(struct dirtree *node)
    {
      int ret = 0;
    
      if (!dirtree_notdotdot(node)) return 0;
    
      if (S_ISDIR(node->st.st_mode) && !node->parent) { //add root dirs.
        add_to_list(node);
        return (DIRTREE_RECURSE|DIRTREE_SYMFOLLOW);
      }
    
      if (S_ISDIR(node->st.st_mode) && FLAG(r)) {
        if (!FLAG(N)) ret = skip(node);
        if (!ret) return DIRTREE_RECURSE|DIRTREE_SYMFOLLOW;
        else {
          add_to_list(node); //only at one side.
          return 0;
        }
      } else {
        add_to_list(node);
        return S_ISDIR(node->st.st_mode) ? 0 : (DIRTREE_RECURSE|DIRTREE_SYMFOLLOW);
      }
    }
    
    static int cmp(void *p1, void *p2)
    {
       return strcmp(*(char **)p1, *(char **)p2);
    }
    
    // quote and escape filenames that have awkward characters
    char *quote_filename(char *filename)
    {
      char *to = "abfnrtv\"\\", *from = "\a\b\f\n\r\t\v\"\\", *s, *t=0, *u;
      int len, quote = 0;
    
      for (;;) {
        // measure escapes on first pass, write on second
        len = 0;
        for (s = filename; *s; s++) {
          if ((u = strchr(from, *s))) {
            if (t) t[len] = '\\', t[len+1] = to[u-from];
            len += 2;
          } else if (*s<0x20 || *s>=0x80)
            len += snprintf(t+len, 5*!!t, "\\%.3o", *s);
          else {
            if (t) t[len] = *s;
            len++;
          }
        }
        if (t) {
          if (quote) t[len++] = '"';
          t[len] = 0;
    
          return t-quote;
        }
    
        // construct the new string
        quote = strlen(filename)!=len || strchr(filename, ' ');
        t = xmalloc(len+1+2*quote);
        if (quote) *t++ = '"';
      }
    }
    
    static void show_label(char *prefix, char *filename, struct stat *sb)
    {
      char date[36];
      char *quoted_file;
    
      quoted_file = quote_filename(filename);
      printf("%s %s\t%s\n", prefix, quoted_file,
        format_iso_time(date, sizeof(date), &sb->st_mtim));
      free(quoted_file);
    }
    
    static void do_diff(char **files)
    {
      long i = 1, size = 1, x = 0, change = 0, ignore_white,
       start1, end1, start2, end2;
      struct diff *d;
      struct arg_list *llist = TT.L;
      int *J;
      regex_t reg;
      
      TT.offset[0] = TT.offset[1] = NULL;
      J = diff(files);
    
      if (!J) return; //No need to compare, have to status only
    
      if (TT.F) {
        xregcomp(®, TT.F, 0);
      }
    
      d = xzalloc(size *sizeof(struct diff));
      do {
        ignore_white = 0;
        for (d[x].a = i; d[x].a<=TT.file[0].len; d[x].a++) {
          if (J[d[x].a] != (J[d[x].a - 1] + 1)) break;
          else continue;
        }
        d[x].c = (J[d[x].a - 1] + 1);
    
        for (d[x].b = (d[x].a - 1); d[x].b<=TT.file[0].len; d[x].b++) {
          if (J[d[x].b + 1]) break;
          else continue;
        }
        d[x].d = (J[d[x].b + 1] - 1);
    
        if (FLAG(B)) {
          if (d[x].a <= d[x].b) {
            if ((TT.offset[0][d[x].b] - TT.offset[0][d[x].a - 1])
                == (d[x].b - d[x].a + 1))
              ignore_white = 1;
          } else if (d[x].c <= d[x].d){
            if ((TT.offset[1][d[x].d] - TT.offset[1][d[x].c - 1])
                == (d[x].d - d[x].c + 1))
              ignore_white = 1;
          }
        }
    
        //is we have diff ?   TODO: lolcat?
        if ((d[x].a <= d[x].b || d[x].c <= d[x].d) && !ignore_white) change = 1;
    
        if (!ignore_white) d = xrealloc(d, (x + 2) *sizeof(struct diff));
        i = d[x].b + 1;
        if (i>TT.file[0].len) break;
        J[d[x].b] = d[x].d;
        if (!ignore_white) x++;
      } while (i<=TT.file[0].len);
    
      i = x+1;
      TT.differ = change; //update status, may change bcoz of -w etc.
    
      if (!FLAG(q) && change) {
        if (!TT.new_line_format) {
          if (FLAG(color)) printf("\e[1m");
          if (FLAG(L)) printf("--- %s\n", llist->arg);
          else show_label("---", files[0], &(TT).st[0]);
          if (!FLAG(L) || !llist->next) show_label("+++", files[1], &(TT).st[1]);
          else {
            while (llist->next) llist = llist->next;
            printf("+++ %s\n", llist->arg);
          }
          if (FLAG(color)) printf("\e[0m");
        }
    
        struct diff *t, *ptr1 = d, *ptr2 = d;
        while (i) {
          long a,b;
    
          // trim context to file len.
          if (TT.new_line_format || TT.U>TT.file[0].len) TT.U = TT.file[0].len;
          if (ptr1->b < ptr1->a && ptr1->d < ptr1->c) {
            i--;
            continue;
          }
          //Handle the context stuff
          a =  ptr1->a;
          b = minof(TT.file[0].len, ptr1->b);
          if (i == x + 1) ptr1->suff = maxof(1, a-TT.U);
          else if (ptr1[-1].prev >= ptr1->a-TT.U) ptr1->suff = ptr1[-1].prev+1;
          else ptr1->suff =  ptr1->a-TT.U;
    calc_ct:
          if (i > 1) {
            if ((ptr2->b + TT.U) >= (ptr2  + 1)->a) {
              ptr2++;
              i--;
              goto calc_ct;
            } else ptr2->prev = ptr2->b + TT.U;
          } else ptr2->prev = ptr2->b;
          start1 = (ptr2->prev - ptr1->suff + 1);
          end1 = (start1 == 1) ? -1 : start1;
          start2 = maxof(1, ptr1->c - (ptr1->a - ptr1->suff));
          end2 = ptr2->prev - ptr2->b + ptr2->d;
    
          if (!TT.new_line_format) {
            if (FLAG(color)) printf("\e[36m");
            printf("@@ -%ld", start1 ? ptr1->suff: (ptr1->suff -1));
            if (end1 != -1) printf(",%ld ", ptr2->prev-ptr1->suff + 1);
            else putchar(' ');
    
            printf("+%ld", (end2 - start2 + 1) ? start2: (start2 -1));
            if ((end2 - start2 +1) != 1) printf(",%ld ", (end2 - start2 +1));
            else putchar(' ');
            printf("@@");
            if (FLAG(color)) printf("\e[0m");
            if (TT.F) {
              print_line_matching_regex(ptr1->suff-1, ®, TT.offset[0], TT.file[0].fp);
            }
            putchar('\n');
          }
    
          for (t = ptr1; t <= ptr2; t++) {
            if (t==ptr1) print_diff(t->suff, t->a-1, ' ', TT.offset[0], TT.file[0].fp);
            print_diff(t->a, t->b, '-', TT.offset[0], TT.file[0].fp);
            print_diff(t->c, t->d, '+', TT.offset[1], TT.file[1].fp);
            if (t == ptr2)
              print_diff(t->b+1, (t)->prev, ' ', TT.offset[0], TT.file[0].fp);
            else print_diff(t->b+1, (t+1)->a-1, ' ', TT.offset[0], TT.file[0].fp);
          }
          ptr2++;
          ptr1 = ptr2;
          i--;
        } //end of while
      } //End of !FLAG_q
      free(d);
      free(J);
      free(TT.offset[0]);
      free(TT.offset[1]);
    }
    
    static void show_status(char **files)
    {
      if (TT.differ==2) return; // TODO: needed?
      if (TT.differ ? FLAG(q) || TT.is_binary : FLAG(s))
        printf("Files %s and %s %s\n", files[0], files[1],
          TT.differ ? "differ" : "are identical");
    }
    
    static void create_empty_entry(int l , int r, int j)
    {
      struct stat st[2];
      char *f[2], *path[2];
      int i;
    
      for (i = 0; i < 2; i++) {
        if (j) {
          if (!FLAG(N) || i!=(j>0)) continue;
          path[!i] = concat_file_path(TT.dir[!i].list[0],
            TT.dir[i].list[i ? r : l]+TT.len[i]);
          f[!i] = "/dev/null";
        }
        path[i] = f[i] = TT.dir[i].list[i ? r : l];
        stat(f[i], st+i);
        if (j) st[!i] = st[i];
      }
    
      for (i = 0; i<2; i++) {
        if (!S_ISREG(st[i].st_mode) && !S_ISDIR(st[i].st_mode)) {
          printf("File %s is not a regular file or directory and was skipped\n",
            path[i]);
          break;
        }
      }
    
      if (i != 2);
      else if (S_ISDIR(st[0].st_mode) && S_ISDIR(st[1].st_mode))
        printf("Common subdirectories: %s and %s\n", path[0], path[1]);
      else if ((i = S_ISDIR(st[0].st_mode)) != S_ISDIR(st[1].st_mode)) {
        char *fidir[] = {"directory", "regular file"};
        printf("File %s is a %s while file %s is a %s\n",
          path[0], fidir[!i], path[1], fidir[i]);
      } else {
        do_diff(f);
        show_status(path);
        if (TT.file[0].fp) fclose(TT.file[0].fp);
        if (TT.file[1].fp) fclose(TT.file[1].fp);
      }
    
      if (FLAG(N) && j) free(path[j<=0]);
    }
    
    static void diff_dir(int *start)
    {
      int l, r, j = 0;
    
      l = start[0]; //left side file start
      r = start[1]; //right side file start
      while (l < TT.dir[0].nr_elm && r < TT.dir[1].nr_elm) {
        if ((j = strcmp (TT.dir[0].list[l]+TT.len[0],
                (TT.dir[1].list[r]+TT.len[1]))) && !FLAG(N)) {
          if (j > 0) {
            printf("Only in %s: %s\n", TT.dir[1].list[0], TT.dir[1].list[r]+TT.len[1]);
            free(TT.dir[1].list[r++]);
          } else {
            printf ("Only in %s: %s\n", TT.dir[0].list[0], TT.dir[0].list[l]+TT.len[0]);
            free(TT.dir[0].list[l++]);
          }
          TT.differ = 1;
        } else {
          create_empty_entry(l, r, j); //create non empty dirs/files if -N.
          if (j>=0) free(TT.dir[1].list[r++]);
          if (j<=0) free(TT.dir[0].list[l++]);
        }
      }
    
      if (l == TT.dir[0].nr_elm) {
        while (r<TT.dir[1].nr_elm) {
          if (!FLAG(N)) {
            printf ("Only in %s: %s\n", TT.dir[1].list[0], TT.dir[1].list[r]+TT.len[1]);
            TT.differ = 1;
          } else create_empty_entry(l, r, 1);
          free(TT.dir[1].list[r++]);
        }
      } else if (r == TT.dir[1].nr_elm) {
        while (l<TT.dir[0].nr_elm) {
          if (!FLAG(N)) {
            printf ("Only in %s: %s\n", TT.dir[0].list[0], TT.dir[0].list[l]+TT.len[0]);
            TT.differ = 1;
          } else create_empty_entry(l, r, -1);
          free(TT.dir[0].list[l++]);
        }
      }
      free(TT.dir[0].list[0]); //we are done, free root nodes too
      free(TT.dir[0].list);
      free(TT.dir[1].list[0]);
      free(TT.dir[1].list);
    }
    
    void diff_main(void)
    {
      int j = 0, k = 1, start[2] = {1, 1};
      char **files = toys.optargs;
    
      toys.exitval = 2;
      if (FLAG(color) && !isatty(1)) toys.optflags ^= FLAG_color;
    
      for (j = 0; j < 2; j++) {
        if (IS_STDIN(files[j])) fstat(0, &TT.st[j]);
        else xstat(files[j], &TT.st[j]);
      }
    
      if (S_ISDIR(TT.st[0].st_mode) != S_ISDIR(TT.st[1].st_mode))
        error_exit("can't compare directory to non-directory");
    
      if (TT.unchanged_line_format || TT.old_line_format || TT.new_line_format) {
        if (S_ISDIR(TT.st[0].st_mode) && S_ISDIR(TT.st[1].st_mode))
          error_exit("can't use line format with directories");
        if (!TT.unchanged_line_format) TT.unchanged_line_format = "%l\n";
        if (!TT.old_line_format) TT.old_line_format = "%l\n";
        if (!TT.new_line_format) TT.new_line_format = "%l\n";
      }
    
      if (same_file(TT.st, TT.st+1)) {
        toys.exitval = 0;
        return show_status(files);
      }
    
      if (S_ISDIR(TT.st[0].st_mode) && S_ISDIR(TT.st[1].st_mode)) {
        for (j = 0; j < 2; j++) {
          memset(TT.dir+j, 0, sizeof(*TT.dir));
          dirtree_flagread(files[j], DIRTREE_SYMFOLLOW, list_dir);
          TT.dir[j].nr_elm = TT.size; //size updated in list_dir
          qsort(&TT.dir[j].list[1], TT.size-1, sizeof(char *), (void *)cmp);
    
          TT.len[j] = strlen(TT.dir[j].list[0]); //calc root node len
          TT.len[j] += TT.dir[j].list[0][TT.len[j]-1] != '/';
    
          if (FLAG(S)) {
            while (k<TT.size && strcmp(TT.dir[j].list[k]+TT.len[j], TT.S)<0) {
              start[j]++;
              k++;
            }
          }
          TT.dir_num++;
          TT.size = 0;
          k = 1;
        }
        diff_dir(start);
      } else {
        if (S_ISDIR(TT.st[0].st_mode) || S_ISDIR(TT.st[1].st_mode)) {
          int d = S_ISDIR(TT.st[0].st_mode);
          char *slash = strrchr(files[d], '/');
    
          files[!d] = concat_file_path(files[!d], slash ? slash+1 : files[d]);
          if (stat(files[!d], &TT.st[!d])) perror_exit("%s", files[!d]);
        }
        do_diff(files);
        show_status(files);
        if (TT.file[0].fp) fclose(TT.file[0].fp);
        if (TT.file[1].fp) fclose(TT.file[1].fp);
      }
      toys.exitval = TT.differ; //exit status will be the status
    }