1 files changed, 274 insertions, 0 deletions
diff --git a/src/expand-common.c b/src/expand-common.c
new file mode 100644
index 000000000..41d7003a4
--- /dev/null
+++ b/src/expand-common.c
@@ -0,0 +1,274 @@
+/* expand-common - common functionality for expand/unexapnd
+   Copyright (C) 1989-2016 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <sys/types.h>
+#include "system.h"
+#include "error.h"
+#include "fadvise.h"
+#include "quote.h"
+#include "xstrndup.h"
+
+#include "expand-common.h"
+
+/* If true, convert blanks even after nonblank characters have been
+   read on the line.  */
+bool convert_entire_line = false;
+
+/* If nonzero, the size of all tab stops.  If zero, use 'tab_list' instead.  */
+static uintmax_t tab_size = 0;
+
+/* The maximum distance between tab stops.  */
+size_t max_column_width;
+
+/* Array of the explicit column numbers of the tab stops;
+   after 'tab_list' is exhausted, each additional tab is replaced
+   by a space.  The first column is column 0.  */
+static uintmax_t *tab_list = NULL;
+
+/* The number of allocated entries in 'tab_list'.  */
+static size_t n_tabs_allocated = 0;
+
+/* The index of the first invalid element of 'tab_list',
+   where the next element can be added.  */
+static size_t first_free_tab = 0;
+
+/* Null-terminated array of input filenames.  */
+static char **file_list = NULL;
+
+/* Default for 'file_list' if no files are given on the command line.  */
+static char *stdin_argv[] =
+{
+  (char *) "-", NULL
+};
+
+/* True if we have ever read standard input.  */
+static bool have_read_stdin = false;
+
+/* The desired exit status.  */
+int exit_status = EXIT_SUCCESS;
+
+
+
+/* Add tab stop TABVAL to the end of 'tab_list'.  */
+extern void
+add_tab_stop (uintmax_t tabval)
+{
+  uintmax_t prev_column = first_free_tab ? tab_list[first_free_tab - 1] : 0;
+  uintmax_t column_width = prev_column <= tabval ? tabval - prev_column : 0;
+
+  if (first_free_tab == n_tabs_allocated)
+    tab_list = X2NREALLOC (tab_list, &n_tabs_allocated);
+  tab_list[first_free_tab++] = tabval;
+
+  if (max_column_width < column_width)
+    {
+      if (SIZE_MAX < column_width)
+        error (EXIT_FAILURE, 0, _("tabs are too far apart"));
+      max_column_width = column_width;
+    }
+}
+
+/* Add the comma or blank separated list of tab stops STOPS
+   to the list of tab stops.  */
+extern void
+parse_tab_stops (char const *stops)
+{
+  bool have_tabval = false;
+  uintmax_t tabval IF_LINT ( = 0);
+  char const *num_start IF_LINT ( = NULL);
+  bool ok = true;
+
+  for (; *stops; stops++)
+    {
+      if (*stops == ',' || isblank (to_uchar (*stops)))
+        {
+          if (have_tabval)
+            add_tab_stop (tabval);
+          have_tabval = false;
+        }
+      else if (ISDIGIT (*stops))
+        {
+          if (!have_tabval)
+            {
+              tabval = 0;
+              have_tabval = true;
+              num_start = stops;
+            }
+
+          /* Detect overflow.  */
+          if (!DECIMAL_DIGIT_ACCUMULATE (tabval, *stops - '0', uintmax_t))
+            {
+              size_t len = strspn (num_start, "0123456789");
+              char *bad_num = xstrndup (num_start, len);
+              error (0, 0, _("tab stop is too large %s"), quote (bad_num));
+              free (bad_num);
+              ok = false;
+              stops = num_start + len - 1;
+            }
+        }
+      else
+        {
+          error (0, 0, _("tab size contains invalid character(s): %s"),
+                 quote (stops));
+          ok = false;
+          break;
+        }
+    }
+
+  if (!ok)
+    exit (EXIT_FAILURE);
+
+  if (have_tabval)
+    add_tab_stop (tabval);
+}
+
+/* Check that the list of tab stops TABS, with ENTRIES entries,
+   contains only nonzero, ascending values.  */
+
+static void
+validate_tab_stops (uintmax_t const *tabs, size_t entries)
+{
+  uintmax_t prev_tab = 0;
+  size_t i;
+
+  for (i = 0; i < entries; i++)
+    {
+      if (tabs[i] == 0)
+        error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
+      if (tabs[i] <= prev_tab)
+        error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
+      prev_tab = tabs[i];
+    }
+}
+
+/* Called after all command-line options have been parsed,
+   and add_tab_stop/parse_tab_stops have been called.
+   Will validate the tab-stop values,
+   and set the final values to:
+   tab-stops = 8 (if no tab-stops given on command line)
+   tab-stops = N (if value N specified as the only value).
+   tab-stops = distinct values given on command line (if multiple values given).
+*/
+extern void
+finalize_tab_stops (void)
+{
+  validate_tab_stops (tab_list, first_free_tab);
+
+  if (first_free_tab == 0)
+    tab_size = max_column_width = 8;
+  else if (first_free_tab == 1)
+    tab_size = tab_list[0];
+  else
+    tab_size = 0;
+}
+
+
+extern uintmax_t
+get_next_tab_column (const uintmax_t column, size_t* tab_index,
+                     bool* last_tab)
+{
+  *last_tab = false;
+
+  /* single tab-size - return multiples of it */
+  if (tab_size)
+    return column + (tab_size - column % tab_size);
+
+  /* multiple tab-sizes - iterate them until the tab position is beyond
+     the current input column. */
+  for ( ; *tab_index < first_free_tab ; (*tab_index)++ )
+    {
+        uintmax_t tab = tab_list[*tab_index];
+        if (column < tab)
+            return tab;
+    }
+
+  *last_tab = true;
+  return 0;
+}
+
+
+
+
+/* Sets new file-list */
+extern void
+set_file_list (char **list)
+{
+  have_read_stdin = false;
+
+  if (!list)
+    file_list = stdin_argv;
+  else
+    file_list = list;
+}
+
+/* Close the old stream pointer FP if it is non-NULL,
+   and return a new one opened to read the next input file.
+   Open a filename of '-' as the standard input.
+   Return NULL if there are no more input files.  */
+
+extern FILE *
+next_file (FILE *fp)
+{
+  static char *prev_file;
+  char *file;
+
+  if (fp)
+    {
+      if (ferror (fp))
+        {
+          error (0, errno, "%s", quotef (prev_file));
+          exit_status = EXIT_FAILURE;
+        }
+      if (STREQ (prev_file, "-"))
+        clearerr (fp);		/* Also clear EOF.  */
+      else if (fclose (fp) != 0)
+        {
+          error (0, errno, "%s", quotef (prev_file));
+          exit_status = EXIT_FAILURE;
+        }
+    }
+
+  while ((file = *file_list++) != NULL)
+    {
+      if (STREQ (file, "-"))
+        {
+          have_read_stdin = true;
+          fp = stdin;
+        }
+      else
+        fp = fopen (file, "r");
+      if (fp)
+        {
+          prev_file = file;
+          fadvise (fp, FADVISE_SEQUENTIAL);
+          return fp;
+        }
+      error (0, errno, "%s", quotef (file));
+      exit_status = EXIT_FAILURE;
+    }
+  return NULL;
+}
+
+/* */
+extern void
+cleanup_file_list_stdin (void)
+{
+    if (have_read_stdin && fclose (stdin) != 0)
+      error (EXIT_FAILURE, errno, "-");
+}