[PATCH v2] system_data_types.7: Specify the length modifiers for the variables that have them

[Alejandro Colomar <colomar.6.4.3@gmail.com>]

Reported-by: Florian Weimer <fweimer@redhat.com>
Reported-by: Paul Eggert <eggert@cs.ucla.edu>
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
---

Hello Paul,

On 9/18/20 10:24 PM, Paul Eggert wrote:
> I suggest saying "values" instead of "variables", here and elsewhere,
> since variables need not be involved.

Yes.

> This sort of thing should use ".B" not ".BR". There are multiple
> instances of this.

Oops. A few typos.

> POSIX does provide that length modifier; however, it doesn't say it
> works with ssize_t. I suggest rewording "Glibc provides a length
> modifier" to "Glibc and most other implementations provide a length
> modifier", and changing the last two sentences to:
> 
> 
> Although
> .B z
> works
> for
> .I ssize_t
> on Glibc and most other implementations, portable POSIX programs should
> avoid it, e.g., by converting to
> .I intmax_t
> and using its length modifier.

Much better wording.  Check the new one, please.

Thanks,

Alex

 man7/system_data_types.7 | 56 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index 080f0057f..5128e1f01 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -108,6 +108,22 @@ capable of storing values in the range
 .BR "" [ PTRDIFF_MIN ,
 .BR PTRDIFF_MAX ].
 .IP
+The length modifier for
+.I ptrdiff_t
+for the
+.BR printf (3)
+and the
+.BR scanf (3)
+families of functions is
+.BR t ;
+resulting commonly in
+.B %td
+or
+.B %ti
+for printing
+.I ptrdiff_t
+values.
+.IP
 Conforming to: C99 and later; POSIX.1-2001 and later.
 .IP
 See also the
@@ -343,6 +359,22 @@ it shall be an unsigned integer type
 capable of storing values in the range [0,
 .BR SIZE_MAX ].
 .IP
+The length modifier for
+.I size_t
+for the
+.BR printf (3)
+and the
+.BR scanf (3)
+families of functions is
+.BR z ;
+resulting commonly in
+.B %zu
+or
+.B %zx
+for printing
+.I size_t
+values.
+.IP
 Conforming to: C99 and later; POSIX.1-2001 and later.
 .IP
 Notes:
@@ -403,6 +435,30 @@ According to POSIX, it shall be a signed integer type
 capable of storing values at least in the range [-1,
 .BR SSIZE_MAX ].
 .IP
+Glibc and most other implementations provide a length modifier for
+.I ssize_t
+for the
+.BR printf (3)
+and the
+.BR scanf (3)
+families of functions, which is
+.BR z ;
+resulting commonly in
+.B %zd
+or
+.B %zi
+for printing
+.I ssize_t
+values.
+Although
+.B z
+works for
+.I ssize_t
+on most implementations, portable POSIX programs should avoid using it,
+e.g., by converting the value to
+.I intmax_t
+and using its length modifier.
+.IP
 Conforming to: POSIX.1-2001 and later.
 .IP
 See also:
-- 
2.28.0