| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- Copyright (C) 1988-2015 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 or |
| any later version published by the Free Software Foundation; with the |
| Invariant Sections being "Free Software" and "Free Software Needs |
| Free Documentation", with the Front-Cover Texts being "A GNU Manual," |
| and with the Back-Cover Texts as in (a) below. |
| |
| (a) The FSF's Back-Cover Text is: "You are free to copy and modify |
| this GNU Manual. Buying copies from GNU Press supports the FSF in |
| developing GNU and promoting software freedom." --> |
| <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Debugging with GDB: read</title> |
| |
| <meta name="description" content="Debugging with GDB: read"> |
| <meta name="keywords" content="Debugging with GDB: read"> |
| <meta name="resource-type" content="document"> |
| <meta name="distribution" content="global"> |
| <meta name="Generator" content="makeinfo"> |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
| <link href="index.html#Top" rel="start" title="Top"> |
| <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="List-of-Supported-Calls.html#List-of-Supported-Calls" rel="up" title="List of Supported Calls"> |
| <link href="write.html#write" rel="next" title="write"> |
| <link href="close.html#close" rel="prev" title="close"> |
| <style type="text/css"> |
| <!-- |
| a.summary-letter {text-decoration: none} |
| blockquote.smallquotation {font-size: smaller} |
| div.display {margin-left: 3.2em} |
| div.example {margin-left: 3.2em} |
| div.indentedblock {margin-left: 3.2em} |
| div.lisp {margin-left: 3.2em} |
| div.smalldisplay {margin-left: 3.2em} |
| div.smallexample {margin-left: 3.2em} |
| div.smallindentedblock {margin-left: 3.2em; font-size: smaller} |
| div.smalllisp {margin-left: 3.2em} |
| kbd {font-style:oblique} |
| pre.display {font-family: inherit} |
| pre.format {font-family: inherit} |
| pre.menu-comment {font-family: serif} |
| pre.menu-preformatted {font-family: serif} |
| pre.smalldisplay {font-family: inherit; font-size: smaller} |
| pre.smallexample {font-size: smaller} |
| pre.smallformat {font-family: inherit; font-size: smaller} |
| pre.smalllisp {font-size: smaller} |
| span.nocodebreak {white-space:nowrap} |
| span.nolinebreak {white-space:nowrap} |
| span.roman {font-family:serif; font-weight:normal} |
| span.sansserif {font-family:sans-serif; font-weight:normal} |
| ul.no-bullet {list-style: none} |
| --> |
| </style> |
| |
| |
| </head> |
| |
| <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> |
| <a name="read"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="write.html#write" accesskey="n" rel="next">write</a>, Previous: <a href="close.html#close" accesskey="p" rel="prev">close</a>, Up: <a href="List-of-Supported-Calls.html#List-of-Supported-Calls" accesskey="u" rel="up">List of Supported Calls</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="read-1"></a> |
| <h4 class="unnumberedsubsubsec">read</h4> |
| <a name="index-read_002c-file_002di_002fo-system-call"></a> |
| |
| <dl compact="compact"> |
| <dt>Synopsis:</dt> |
| <dd><div class="smallexample"> |
| <pre class="smallexample">int read(int fd, void *buf, unsigned int count); |
| </pre></div> |
| |
| </dd> |
| <dt>Request:</dt> |
| <dd><p>‘<samp>Fread,<var>fd</var>,<var>bufptr</var>,<var>count</var></samp>’ |
| </p> |
| </dd> |
| <dt>Return value:</dt> |
| <dd><p>On success, the number of bytes read is returned. |
| Zero indicates end of file. If count is zero, read |
| returns zero as well. On error, -1 is returned. |
| </p> |
| </dd> |
| <dt>Errors:</dt> |
| <dd> |
| <dl compact="compact"> |
| <dt><code>EBADF</code></dt> |
| <dd><p><var>fd</var> is not a valid file descriptor or is not open for |
| reading. |
| </p> |
| </dd> |
| <dt><code>EFAULT</code></dt> |
| <dd><p><var>bufptr</var> is an invalid pointer value. |
| </p> |
| </dd> |
| <dt><code>EINTR</code></dt> |
| <dd><p>The call was interrupted by the user. |
| </p></dd> |
| </dl> |
| |
| </dd> |
| </dl> |
| |
| |
| |
| |
| </body> |
| </html> |
