Module Name: src Committed By: dholland Date: Thu Jul 23 02:54:27 UTC 2009
Modified Files: src/lib/libc/stdlib: strtol.3 strtoul.3 Log Message: Clarify the description of the errno behavior, based on the recent thread in tech-userlevel. To generate a diff of this commit: cvs rdiff -u -r1.24 -r1.25 src/lib/libc/stdlib/strtol.3 cvs rdiff -u -r1.21 -r1.22 src/lib/libc/stdlib/strtoul.3 Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/lib/libc/stdlib/strtol.3 diff -u src/lib/libc/stdlib/strtol.3:1.24 src/lib/libc/stdlib/strtol.3:1.25 --- src/lib/libc/stdlib/strtol.3:1.24 Thu May 21 09:13:35 2009 +++ src/lib/libc/stdlib/strtol.3 Thu Jul 23 02:54:27 2009 @@ -1,4 +1,4 @@ -.\" $NetBSD: strtol.3,v 1.24 2009/05/21 09:13:35 wiz Exp $ +.\" $NetBSD: strtol.3,v 1.25 2009/07/23 02:54:27 dholland Exp $ .\" .\" Copyright (c) 1990, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -193,17 +193,22 @@ is set to .Er EINVAL and the functions return 0. +.Pp +If no error occurs, +.Va errno +is left unchanged. +This behavior (which is unlike most library functions) is guaranteed +by the pertinent standards. .Sh EXAMPLES -Ensuring that a string is a valid number (i.e., in range and containing no -trailing characters) requires clearing +Because the return value of +.Fn strtol +cannot be used unambiguously to detect an error, .Va errno -beforehand explicitly since +is left unchanged after a successful call. +To ensure that a string is a valid number (i.e., in range and containing no +trailing characters), clear .Va errno -is not changed on a successful call to -.Fn strtol , -and the return value of -.Fn strtol -cannot be used unambiguously to signal an error: +beforehand explicitly, then check it afterwards: .Bd -literal -offset indent char *ep; long lval; Index: src/lib/libc/stdlib/strtoul.3 diff -u src/lib/libc/stdlib/strtoul.3:1.21 src/lib/libc/stdlib/strtoul.3:1.22 --- src/lib/libc/stdlib/strtoul.3:1.21 Thu May 21 09:13:35 2009 +++ src/lib/libc/stdlib/strtoul.3 Thu Jul 23 02:54:27 2009 @@ -1,4 +1,4 @@ -.\" $NetBSD: strtoul.3,v 1.21 2009/05/21 09:13:35 wiz Exp $ +.\" $NetBSD: strtoul.3,v 1.22 2009/07/23 02:54:27 dholland Exp $ .\" .\" Copyright (c) 1990, 1991, 1993 .\" The Regents of the University of California. All rights reserved. @@ -191,17 +191,22 @@ is set to .Er EINVAL and the functions return 0. +.Pp +If no error occurs, +.Va errno +is left unchanged. +This behavior (which is unlike most library functions) is guaranteed +by the pertinent standards. .Sh EXAMPLES -Ensuring that a string is a valid number (i.e., in range and containing no -trailing characters) requires clearing +Because the return value of +.Fn strtoul +cannot be used unambiguously to detect an error, .Va errno -beforehand explicitly since +is left unchanged after a successful call. +To ensure that a string is a valid number (i.e., in range and containing no +trailing characters), clear .Va errno -is not changed on a successful call to -.Fn strtoul , -and the return value of -.Fn strtoul -cannot be used unambiguously to signal an error: +beforehand explicitly, then check it afterwards: .Bd -literal -offset indent char *ep; unsigned long ulval;