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| author | Alejandro Colomar <alx.manpages@gmail.com> | 2022-04-16 20:03:16 +0200 |
|---|---|---|
| committer | Alejandro Colomar <alx.manpages@gmail.com> | 2022-04-16 20:03:19 +0200 |
| commit | c4693f86a8af6bca1e42a91e12acd1568ec077fd (patch) | |
| tree | facd86ec62aff9f02be2cff61240ba1cfb521e4e /man3 | |
| parent | 5c405d85faeba07a68cfda566b7cb99a0d935c88 (diff) | |
| download | man-pages-c4693f86a8af6bca1e42a91e12acd1568ec077fd.tar.gz | |
scanf.3: Clarify ll and L modifiers
Relevant documents:
POSIX:
<https://pubs.opengroup.org/onlinepubs/9699919799/functions/fscanf.html>
glibc:
<https://www.gnu.org/software/libc/manual/html_mono/libc.html#Numeric-Input-Conversions>
ISO C2x:
<http://www.open-std.org/JTC1/SC22/WG14/www/docs/n2731.pdf#subsubsection.7.21.6.2>
Still, from the documentation linked above, it seems to me that
"%Ln" is supported as a glibc extension, and doesn't fall into
"either no effect or undefined behavior" as says the GCC warning
shown in the bugzilla report. I didn't modify the documentation
regarding %n, and recommend investigating a possible GCC bug.
Reported-by: Avinash Sonawane <rootkea@gmail.com>
Link: bugzilla <https://bugzilla.kernel.org/show_bug.cgi?id=215844>
Cc: glibc <libc-alpha@sourceware.org>
Cc: GCC <gcc@gcc.gnu.org>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Diffstat (limited to 'man3')
| -rw-r--r-- | man3/scanf.3 | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/man3/scanf.3 b/man3/scanf.3 index 55058f3d26..199c8a19a9 100644 --- a/man3/scanf.3 +++ b/man3/scanf.3 @@ -308,10 +308,6 @@ and the next pointer is a pointer to .I double (rather than .IR float ). -Specifying two -.B l -characters is equivalent to -.BR L . If used with .B %c or @@ -320,12 +316,33 @@ the corresponding parameter is considered as a pointer to a wide character or wide-character string respectively. .\" This use of l was introduced in Amendment 1 to ISO C90. .TP +.B ll +(ell-ell) +Indicates that the conversion will be one of +.BR b , +.BR d , +.BR i , +.BR o , +.BR u , +.BR x , +.BR X , +or +.B n +and the next pointer is a pointer to a +.I long long +or +.I unsigned long long +(rather than +.IR int ). +.TP .B L Indicates that the conversion will be either \fBe\fP, \fBf\fP, or \fBg\fP and the next pointer is a pointer to .I "long double" -or the conversion will be +or +(as a GNU extension) +the conversion will be \fBd\fP, \fBi\fP, \fBo\fP, \fBu\fP, or \fBx\fP and the next pointer is a pointer to .IR "long long" . @@ -683,17 +700,17 @@ floating-point conversion specifier (and is unaffected by etc.). .SH BUGS All functions are fully C89 conformant, but provide the -additional specifiers +additional modifiers .B q and .B a as well as an additional behavior of the .B L and -.B l -specifiers. +.B ll +modifiers. The latter may be considered to be a bug, as it changes the -behavior of specifiers defined in C89. +behavior of modifiers defined in C89. .PP Some combinations of the type modifiers and conversion specifiers defined by ANSI C do not make sense |