X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fstr.c;h=b169f0d7613ee556e7a5a32e746a36ac2f06af23;hb=c725a4f64718ef1ee4139c27c94b2eb6447b51b4;hp=13c081dda71e0122d4fac98f2f62053fee4d44e2;hpb=9f087e7aa4cdff1d5d46d5e188c0017a9d2d0029;p=pspp-builds.git

diff --git a/src/libpspp/str.c b/src/libpspp/str.c
index 13c081dd..b169f0d7 100644
--- a/src/libpspp/str.c
+++ b/src/libpspp/str.c
@@ -19,14 +19,14 @@
 #include "str.h"
 
 #include <ctype.h>
-#include <limits.h>
+#include <errno.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 #include <libpspp/message.h>
 #include <libpspp/pool.h>
 
 #include "minmax.h"
-#include "size_max.h"
 #include "xalloc.h"
 #include "xsize.h"
 
@@ -252,6 +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 *
@@ -1218,8 +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)
@@ -1228,12 +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. */