diff options
Diffstat (limited to 'manual/stdio.texi')
| -rw-r--r-- | manual/stdio.texi | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/manual/stdio.texi b/manual/stdio.texi index 04c635b054..103be34abb 100644 --- a/manual/stdio.texi +++ b/manual/stdio.texi @@ -1479,9 +1479,9 @@ the @var{size} argument specifies the maximum number of characters to produce. The trailing null character is counted towards this limit, so you should allocate at least @var{size} characters for the string @var{s}. -The return value is the number of characters stored, not including the -terminating null. If this value equals @code{@var{size} - 1}, then -there was not enough space in @var{s} for all the output. You should +The return value is the number of characters which are generated for the +given input. If this value is greater than @var{size}, not all +characters from the result have been stored in @var{s}. You should try again with a bigger output string. Here is an example of doing this: @@ -1495,21 +1495,24 @@ make_message (char *name, char *value) /* @r{Guess we need no more than 100 chars of space.} */ int size = 100; char *buffer = (char *) xmalloc (size); + int nchars; @end group @group - while (1) + /* @r{Try to print in the allocated space.} */ + nchars = snprintf (buffer, size, "value of %s is %s", + name, value); +@end group +@group + if (nchars) >= size) @{ - /* @r{Try to print in the allocated space.} */ - int nchars = snprintf (buffer, size, - "value of %s is %s", - name, value); - /* @r{If that worked, return the string.} */ - if (nchars < size) - return buffer; - /* @r{Else try again with twice as much space.} */ - size *= 2; - buffer = (char *) xrealloc (size, buffer); + /* @r{Reallocate buffer now that we know how much space is needed.} */ + buffer = (char *) xrealloc (buffer, nchars + 1); + + /* @r{Try again.} */ + snprintf (buffer, size, "value of %s is %s", name, value); @} + /* @r{The last call worked, return the string.} */ + return buffer; @} @end group @end smallexample |