From: Alejandro Colomar <alx@kernel.org>
Date: Fri, 21 Mar 2025 22:13:50 +0000 (+0100)
Subject: man/man3/strtol.3: CAVEATS: Clarify how to perform range checks
X-Git-Tag: man-pages-6.14~45
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f4d8a396bde29a21775cc0403c64a1d7c2b16c1;p=thirdparty%2Fman-pages.git

man/man3/strtol.3: CAVEATS: Clarify how to perform range checks

Reported-by: Bruno Haible <bruno@clisp.org>
Co-authored-by: Bruno Haible <bruno@clisp.org>
Signed-off-by: Bruno Haible <bruno@clisp.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---

diff --git a/man/man3/strtol.3 b/man/man3/strtol.3
index f9c9af4bc..2ae48119b 100644
--- a/man/man3/strtol.3
+++ b/man/man3/strtol.3
@@ -192,6 +192,7 @@ POSIX.1-2001, C89, SVr4, 4.3BSD.
 .BR strtoll ()
 POSIX.1-2001, C99.
 .SH CAVEATS
+.SS Range checks
 Since
 .BR strtol ()
 can legitimately return 0,
@@ -210,6 +211,19 @@ and then determine if an error occurred by checking whether
 .I errno == ERANGE
 after the call.
 .P
+.in +4n
+.EX
+errno = 0;
+n = strtol(s, &end, base);
+if (end == s)
+	goto no_number;
+if ((errno == ERANGE && n == LONG_MIN) || n < min)
+	goto too_low;
+if ((errno == ERANGE && n == LONG_MAX) || n > max)
+	goto too_high;
+.EE
+.in
+.SS base
 If the
 .I base
 needs to be tested,