<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<!--Converted with LaTeX2HTML 96.1-c (Feb 29, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds -->
<HTML>
<HEAD>
<TITLE>8.1.1 Formatted Output</TITLE>
<META NAME="description" CONTENT="8.1.1 Formatted Output">
<META NAME="keywords" CONTENT="lpg">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<LINK REL=STYLESHEET HREF="lpg.css">
</HEAD>
<BODY LANG="EN">
<A NAME="tex2html1483" HREF="node88.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="/icons//next_motif.gif"></A> <A NAME="tex2html1481" HREF="node86.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="/icons//up_motif.gif"></A> <A NAME="tex2html1475" HREF="node86.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="/icons//previous_motif.gif"></A> <A NAME="tex2html1485" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="/icons//contents_motif.gif"></A> <BR>
<B> Next:</B> <A NAME="tex2html1484" HREF="node88.html">8.1.2 Formatted Input</A>
<B>Up:</B> <A NAME="tex2html1482" HREF="node86.html">8.1 I/O Function in </A>
<B> Previous:</B> <A NAME="tex2html1476" HREF="node86.html">8.1 I/O Function in </A>
<BR> <P>
<H2><A NAME="SECTION00911000000000000000">8.1.1 Formatted Output</A></H2>
<A NAME="sec_formout"> </A>
<P>
The <B>printf(...)</B> functions in provide formatted output
and allow transformations of the arguments.
<P>
<UL><LI> <TT>int fprintf(FILE *stream, const char *format, ...),</TT> <A NAME="fun_fprintf"> </A><BR>
will transform the output (arguments to fill in <TT>...</TT>) and
write it to <TT>stream</TT>. The format defined in <TT>format</TT>
will be written, too. The function will return the number of written
characters or a negative value on error.
<P>
<TT>format</TT> contains two kinds of objects
<OL><LI> normal characters for the output and<LI> information how to transform or format the arguments.
</OL>
<P>
Format information must begin with <I>%</I> followed by values for the
format followed by a character for the translation (to print % by
itself use <I>%%</I>). Possible values for the format are:
<P>
<UL><LI> Flags
<UL><LI> <TT>-</TT> <BR>
The formatted argument will be printed on the left margin (default is
the right margin in the argument field).<LI> <TT>+</TT> <BR>
Every number will be printed with a sign, e.g. <TT>+12</TT> or <TT>-2.32</TT>.
</UL><LI> Blank <BR>
When the first character is not a sign, a blank will be inserted.<LI> <TT>0</TT> <BR>
For numeric transformation the field width will be filled up with <TT>0</TT>'s
on the left side.<LI> <TT>#</TT> <BR>
Alternate output depending on the transformation for the argument
<UL><LI> For <I>o</I> the first number is a <I>0</I>.<LI> For <I>x</I> or <I>X</I> <I>0x</I> or <I>0X</I> will be printed in
front of the argument.<LI> For <I>e</I>, <I>E</I>, <I>f</I> or <I>F</I> the output has a decimal
point.<LI> For <I>g</I> or <I>G</I> zeroes on the end of the argument are
printed.
</UL><LI> A number for the minimal field width.<BR>
The transformed argument is printed in a field which is at least as big as
the argument itself. With a number you can make the field width bigger.
If the formatted argument is smaller, then the field width will be filled
with zeroes or blanks.<LI> A point to separate the field width and the precision.<LI> A number for the precision.
</UL>
<P>
Possible values for the transformation are in table <A HREF="node87.html#tab_printf">8.1</A> on page <A HREF="node87.html#tab_printf"><IMG ALIGN=BOTTOM ALT="gif" SRC="/icons//cross_ref_motif.gif"></A>.<LI> <TT>int printf(const char *format, ...)</TT> <A NAME="fun_printf"> </A><BR>
Same as <B>fprintf(stdout, ...)</B>.<LI> <TT>int sprintf(char *s, const char *format, ...)</TT> <A NAME="fun_sprintf"> </A><BR>
Same as <B>printf(...)</B>, except that the output will be written
to the the character pointer <TT>s</TT> (with a following
<I><code>\</code>0</I>).
<P>
(<B>Note:</B> You must allocate enough memory for <TT>s</TT>.)<LI> <TT>vprintf(const char *format, va_list arg)</TT> <A NAME="fun_vprintf"> </A><BR>
<TT>vfprintf(FILE *stream, const char *format, va_list arg)</TT> <A NAME="fun_vfprintf"> </A><BR>
<TT>vsprintf(char *s, const char *format, va_list arg)</TT> <A NAME="fun_vsprintf"> </A><BR>
The same as the functions above, only the argument list is set to
<TT>arg</TT>.
</UL>
<P>
<P><A NAME="47783"> </A><A NAME="tab_printf"> </A><BR>
<STRONG>Table 8.1:</STRONG> Libc - printf transformations<BR>
<P><HR><A NAME="tex2html1483" HREF="node88.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="/icons//next_motif.gif"></A> <A NAME="tex2html1481" HREF="node86.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="/icons//up_motif.gif"></A> <A NAME="tex2html1475" HREF="node86.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="/icons//previous_motif.gif"></A> <A NAME="tex2html1485" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="/icons//contents_motif.gif"></A> <BR>
<B> Next:</B> <A NAME="tex2html1484" HREF="node88.html">8.1.2 Formatted Input</A>
<B>Up:</B> <A NAME="tex2html1482" HREF="node86.html">8.1 I/O Function in </A>
<B> Previous:</B> <A NAME="tex2html1476" HREF="node86.html">8.1 I/O Function in </A>
<P><ADDRESS>
<I>Converted on: <BR>
Fri Mar 29 14:43:04 EST 1996</I>
</ADDRESS>
</BODY>
</HTML>
