Patch #6386. Thanks to John Darrington for review and for the

[pspp-builds.git] / src / libpspp / str.c

diff --git a/src/libpspp/str.c b/src/libpspp/str.c
index 503d6c8bb9d7ac59f023a1b31722052217bba6f8..b169f0d7613ee556e7a5a32e746a36ac2f06af23 100644 (file)
--- a/src/libpspp/str.c
+++ b/src/libpspp/str.c
@@ -1,35 +1,33 @@
-/* PSPP - computes sample statistics.
+/* PSPP - a program for statistical analysis.
    Copyright (C) 1997-9, 2000, 2006 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 2 of the
-   License, or (at your option) any later version.
+   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.
+   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, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA. */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
 #include <config.h>
 
 #include "str.h"
 
 #include <ctype.h>
-#include <limits.h>
+#include <errno.h>
+#include <stdint.h>
 #include <stdlib.h>
 
-#include <libpspp/alloc.h>
 #include <libpspp/message.h>
 #include <libpspp/pool.h>
 
 #include "minmax.h"
-#include "size_max.h"
+#include "xalloc.h"
 #include "xsize.h"
 \f
 /* Reverses the order of NBYTES bytes at address P, thus converting
@@ -254,6 +252,41 @@ str_lowercase (char *s)
     *s = tolower ((unsigned char) *s);
 }
 
+/* Converts NUMBER into a string in 26-adic notation in BUFFER,
+   which has room for SIZE bytes.  Returns true if successful,
+   false if NUMBER, plus a trailing null, is too large to fit in
+   the available space.
+
+   26-adic notation is "spreadsheet column numbering": 1 = A, 2 =
+   B, 3 = C, ... 26 = Z, 27 = AA, 28 = AB, 29 = AC, ...
+
+   26-adic notation is the special case of a k-adic numeration
+   system (aka bijective base-k numeration) with k=26.  In k-adic
+   numeration, the digits are {1, 2, 3, ..., k} (there is no
+   digit 0), and integer 0 is represented by the empty string.
+   For more information, see
+   http://en.wikipedia.org/wiki/Bijective_numeration. */
+bool
+str_format_26adic (unsigned long int number, char buffer[], size_t size)
+{
+  size_t length = 0;
+
+  while (number-- > 0)
+    {
+      if (length >= size)
+        return false;
+      buffer[length++] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"[number % 26];
+      number /= 26;
+    }
+
+  if (length >= size)
+    return false;
+  buffer[length] = '\0';
+
+  buf_reverse (buffer, length);
+  return true;
+}
+
 /* Formats FORMAT into DST, as with sprintf(), and returns the
    address of the terminating null written to DST. */
 char *
@@ -1220,8 +1253,8 @@ ds_read_config_line (struct string *st, int *line_number, FILE *stream)
 
 /* Attempts to read SIZE * CNT bytes from STREAM and append them
    to ST.
-   Returns number of bytes actually read. */
-size_t
+   Returns true if all the requested data was read, false otherwise. */
+bool
 ds_read_stream (struct string *st, size_t size, size_t cnt, FILE *stream)
 {
   if (size != 0)
@@ -1230,12 +1263,18 @@ ds_read_stream (struct string *st, size_t size, size_t cnt, FILE *stream)
       if (size_in_bounds_p (xsum (ds_length (st), try_bytes)))
         {
           char *buffer = ds_put_uninit (st, try_bytes);
-          size_t got_bytes = fread (buffer, size, cnt, stream);
+          size_t got_bytes = fread (buffer, 1, try_bytes, stream);
           ds_truncate (st, ds_length (st) - (try_bytes - got_bytes));
-          return got_bytes;
+          return got_bytes == try_bytes;
+        }
+      else
+        {
+          errno = ENOMEM;
+          return false;
         }
     }
-  return 0;
+  else
+    return true;
 }
 
 /* Concatenates S onto ST. */