1 files changed, 132 insertions, 0 deletions
diff --git a/libmailutils/string/strtosize.c b/libmailutils/string/strtosize.c
new file mode 100644
index 000000000..a1146a46b
--- /dev/null
+++ b/libmailutils/string/strtosize.c
@@ -0,0 +1,132 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2016-2024 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <mailutils/errno.h>
+#include <mailutils/cctype.h>
+#include <mailutils/cstr.h>
+
+#ifndef SIZE_MAX
+# define SIZE_MAX (~((size_t)0))
+#endif
+
+/*
+ * Converts the initial part of the string in STR to a size_t value.
+ * A valid input consists of a sequence of decimal digits, and optional
+ * size suffix: K, M, or G.  Any amount of whitespace is allowed at the
+ * beginning of STR and between the last digit and size suffix.
+ *
+ * On success, the result is stored in RET_VAL and 0 is returned.
+ * On error, RET_VAL remains untouched and one of the following error
+ * codes is returned:
+ *   EINVAL       - STR is NULL.
+ *   MU_ERR_OUT_PTR_NULL
+ *                RET_VAL is NULL.
+ *   ERANGE       - Result is out of allowed range for size_t.
+ *   MU_ERR_PARSE - (0) Unexpected character encountered or
+ *                  (1) STR is empty or
+ *                  (2) STR contains only whitespace characters or
+ *                  (3) ENDP is NULL and the portion of STR that remains
+ *                  after conversion contains characters other than
+ *                  \0 and whitespace,
+ *
+ * If ENDP is not NULL, a pointer to the character in STR at which
+ * the conversion has stopped is stored in *ENDP.
+ */
+int
+mu_strtosize (char const *str, char **endp, size_t *ret_val)
+{
+  size_t n = 0;
+  int rc = 0;
+  char const *start, *s;
+  
+  if (!str)
+    return EINVAL;
+  if (!ret_val)
+    return MU_ERR_OUT_PTR_NULL;
+
+  s = start = mu_str_skip_class (str, MU_CTYPE_SPACE);
+  
+  while (*s && mu_isdigit (*s))
+    {
+      size_t x = n * 10 + *s - '0';
+      if (x < n)
+	{
+	  rc = ERANGE;
+	  goto end;
+	}
+      n = x;
+      s++;
+    }
+
+  if (s == start)
+    {
+      rc = MU_ERR_PARSE;
+      goto end;
+    }
+
+  str = s;
+  s = mu_str_skip_class (s, MU_CTYPE_SPACE);
+  
+  switch (*s++)
+    {
+    case 'g':
+    case 'G':
+      if (SIZE_MAX / n < 1024)
+	{
+	  rc = ERANGE;
+	  break;
+	}
+      n <<= 10;
+    case 'm':
+    case 'M':
+      if (SIZE_MAX / n < 1024)
+	{
+	  rc = ERANGE;
+	  break;
+	}
+      n <<= 10;
+    case 'k':
+    case 'K':
+      if (SIZE_MAX / n < 1024)
+	{
+	  rc = ERANGE;
+	  break;
+	}
+      n <<= 10;
+      break;
+
+    case 0:
+      s = str;
+      break;
+	
+    default:
+      s = str;
+      rc = MU_ERR_PARSE;
+    }
+ end:
+  if (endp)
+    *endp = (char*) s;
+  else if (rc == 0 && *mu_str_skip_class (s, MU_CTYPE_SPACE))
+    rc = MU_ERR_PARSE;
+    
+  if (rc == 0)
+    *ret_val = n;
+  return rc;
+}