POSIX.1-2008 adopted the m flag for dynamic allocation. Update the scanf
spec to cover it and relegate the glibc-specific a flag to the NOTES.
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
---
man3/scanf.3 | 91 ++++++++++++++++++++++++++++--------------------------------
1 file changed, 42 insertions(+), 49 deletions(-)
diff --git a/man3/scanf.3 b/man3/scanf.3
index 1e6f32d..b8985a3 100644
--- a/man3/scanf.3
+++ b/man3/scanf.3
@@ -47,7 +47,7 @@
.\" Add ERRORS section.
.\" Document the 'a' and 'm' modifiers for dynamic string allocation.
.\"
-.TH SCANF 3 2011-09-28 "GNU" "Linux Programmer's Manual"
+.TH SCANF 3 2013-01-30 "GNU" "Linux Programmer's Manual"
.SH NAME
scanf, fscanf, sscanf, vscanf, vsscanf, vfscanf \- input format conversion
.SH SYNOPSIS
@@ -198,7 +198,7 @@ included in the count of successful assignments returned by
.BR scanf ().
.TP
\(bu
-An optional \(aqa\(aq character.
+An optional \(aqm\(aq character.
This is used with string conversions, and relieves the caller of the
need to allocate a corresponding buffer to hold the input: instead,
.BR scanf ()
@@ -211,9 +211,6 @@ variable (this variable does not need to be initialized before the call).
The caller should subsequently
.BR free (3)
this buffer when it is no longer required.
-This is a GNU extension;
-C99 employs the \(aqa\(aq character as a conversion specifier (and
-it can also be used as such in the GNU implementation).
.TP
\(bu
An optional decimal integer which specifies the
@@ -604,51 +601,13 @@ documentation of
.I libc (glibc-1.08)
for a more concise description.
.SH NOTES
-The GNU C library supports a nonstandard extension that causes
-the library to dynamically allocate a string of sufficient size
-for input strings for the
-.B %s
-and
-\fB%a[\fP\fIrange\fP\fB]\fP
-conversion specifiers.
-.\" This feature seems to be present at least as far back as glibc 2.0.
-To make use of this feature, specify
+The GNU C library supported the dynamic allocation conversion specifier
+(as a nonstandard extension) via the
.B a
-as a length modifier (thus
-.B %as
-or
-\fB%a[\fP\fIrange\fP\fB]\fP).
-The caller must
-.BR free (3)
-the returned string, as in the following example:
-.in +4n
-.nf
-
-char *p;
-int n;
-
-errno = 0;
-n = scanf("%a[a-z]", &p);
-if (n == 1) {
- printf("read: %s\\n", p);
- free(p);
-} else if (errno != 0) {
- perror("scanf");
-} else {
- fprintf(stderr, "No matching characters\\n");
-}
-.fi
-.in
+character. This feature
+seems to be present at least as far back as glibc 2.0.
.PP
-As shown in the above example, it is only necessary to call
-.BR free (3)
-if the
-.BR scanf ()
-call successfully read a string.
-.PP
-The
-.B a
-modifier is not available if the program is compiled with
+It is not available if the program is compiled with
.I "gcc -std=c99"
or
.IR "gcc -D_ISOC99_SOURCE"
@@ -678,7 +637,41 @@ floating-point conversion specifier (and is unaffected by
.IR "gcc -std=c99"
etc.)
.IP *
-It is specified in the upcoming revision of the POSIX.1 standard.
+It is specified in the POSIX.1-2008 standard.
+.SH EXAMPLE
+To use the dynamic allocation conversion specifier, specify
+.B m
+as a length modifier (thus
+.B %ms
+or
+\fB%m[\fP\fIrange\fP\fB]\fP).
+The caller must
+.BR free (3)
+the returned string, as in the following example:
+.in +4n
+.nf
+
+char *p;
+int n;
+
+errno = 0;
+n = scanf("%m[a-z]", &p);
+if (n == 1) {
+ printf("read: %s\\n", p);
+ free(p);
+} else if (errno != 0) {
+ perror("scanf");
+} else {
+ fprintf(stderr, "No matching characters\\n");
+}
+.fi
+.in
+.PP
+As shown in the above example, it is only necessary to call
+.BR free (3)
+if the
+.BR scanf ()
+call successfully read a string.
.SH BUGS
All functions are fully C89 conformant, but provide the
additional specifiers
--
1.8.0.2
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