add strtonum

diff --git a/README.md b/README.md
index cea3998906e487f01e6947ecfbe88ba88e5341e4..8324035f51400315c5fa93d0fd44fadc2e8a7d93 100644 (file)
--- a/README.md
+++ b/README.md
@@ -65,10 +65,16 @@ permuting, defining those enables it per function (GNU behaviour, can still be d
 includes `strdup()` and `strndup()`
 
 `strndup()` follows the latest standard, meaning that it copies at most _n_ chars, not _n_ + 1.
-also, no standard specifies that `strndup()` should return less than _n_ if `strlen(s) + 1` < _n_, but this implementation does so.
+Also, no standard specifies that `strndup()` should return less than _n_ if `strlen(s) + 1` < _n_, but this implementation does so.
 
 ---
 
 ### strlcat
 
 includes `strlcat()` and `strlcpy()`
+
+---
+
+### strtonum
+
+includes `strtonum()`

diff --git a/strtonum.h b/strtonum.h
new file mode 100644 (file)
index 0000000..2cea7dc
--- /dev/null
+++ b/strtonum.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2004 Ted Unangst and Todd Miller
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* https://git.datadissipation.net */
+#ifndef STRTONUM_H_
+ #define STRTONUM_H_            1
+
+ #ifdef STRTONUM_INCLUDE_LIBC
+  #include <errno.h>
+  #include <limits.h>
+  #include <stdlib.h>
+ #endif /* STRTONUM_INCLUDE_LIBC */
+
+ #ifndef HAVE_STRTONUM
+ #define strtonum               i_strtonum_
+long long i_strtonum_(const char *numstr, long long minval, long long maxval,
+                     const char **errstrp);
+ #endif /* !HAVE_STRTONUM */
+
+ #ifdef STRTONUM_IMPLEMENTATION
+  #define      I_INVALID_      1
+  #define      I_TOOSMALL_     2
+  #define      I_TOOLARGE      3
+
+long long
+i_strtonum_(const char *numstr, long long minval, long long maxval,
+           const char **errstrp)
+{
+       long long ll = 0;
+       int error = 0;
+       char *ep;
+       struct errval {
+               const char *errstr;
+               int err;
+       } ev[4] = {
+               { NULL,         0 },
+               { "invalid",    EINVAL },
+               { "too small",  ERANGE },
+               { "too large",  ERANGE },
+       };
+
+       ev[0].err = errno;
+       errno = 0;
+       if (minval > maxval) {
+               error = I_INVALID_;
+       } else {
+               ll = strtoll(numstr, &ep, 10);
+               if (numstr == ep || *ep != '\0')
+                       error = I_INVALID_;
+               else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
+                       error = I_TOOSMALL_;
+               else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
+                       error = I_TOOLARGE;
+       }
+       if (errstrp != NULL)
+               *errstrp = ev[error].errstr;
+       errno = ev[error].err;
+       if (error)
+               ll = 0;
+
+       return (ll);
+}
+ #endif /* STRTONUM_IMPLEMENTATION */
+#endif /* !STRTONUM_H_ */