mingw/info/gdb/Starting.html

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  18
  19 <h3 class="section">Starting your program</h3>
  20
  21      <dl>
  22 <dt><code>run</code>
  23      <dd><dt><code>r</code>
  24      <dd>Use the <code>run</code> command to start your program under GDB.
  25 You must first specify the program name (except on VxWorks) with an
  26 argument to GDB (see <a href="Invocation.html#Invocation">Getting In and Out of GDB</a>), or by using the <code>file</code> or <code>exec-file</code> command
  27 (see <a href="Files.html#Files">Commands to specify files</a>).
  28
  29    </dl>
  30
  31    <p>If you are running your program in an execution environment that
  32 supports processes, <code>run</code> creates an inferior process and makes
  33 that process run your program.  (In environments without processes,
  34 <code>run</code> jumps to the start of your program.)
  35
  36    <p>The execution of a program is affected by certain information it
  37 receives from its superior.  GDB provides ways to specify this
  38 information, which you must do <em>before</em> starting your program.  (You
  39 can change it after starting your program, but such changes only affect
  40 your program the next time you start it.)  This information may be
  41 divided into four categories:
  42
  43      <dl>
  44 <dt>The <em>arguments.</em>
  45      <dd>Specify the arguments to give your program as the arguments of the
  46 <code>run</code> command.  If a shell is available on your target, the shell
  47 is used to pass the arguments, so that you may use normal conventions
  48 (such as wildcard expansion or variable substitution) in describing
  49 the arguments.
  50 In Unix systems, you can control which shell is used with the
  51 <code>SHELL</code> environment variable.
  52 See <a href="Arguments.html#Arguments">Your program's arguments</a>.
  53
  54      <br><dt>The <em>environment.</em>
  55      <dd>Your program normally inherits its environment from GDB, but you can
  56 use the GDB commands <code>set environment</code> and <code>unset
  57 environment</code> to change parts of the environment that affect
  58 your program.  See <a href="Environment.html#Environment">Your program's environment</a>.
  59
  60      <br><dt>The <em>working directory.</em>
  61      <dd>Your program inherits its working directory from GDB.  You can set
  62 the GDB working directory with the <code>cd</code> command in GDB.
  63 See <a href="Working-Directory.html#Working%20Directory">Your program's working directory</a>.
  64
  65      <br><dt>The <em>standard input and output.</em>
  66      <dd>Your program normally uses the same device for standard input and
  67 standard output as GDB is using.  You can redirect input and output
  68 in the <code>run</code> command line, or you can use the <code>tty</code> command to
  69 set a different device for your program.
  70 See <a href="Input-Output.html#Input%2fOutput">Your program's input and output</a>.
  71
  72      <p><em>Warning:</em> While input and output redirection work, you cannot use
  73 pipes to pass the output of the program you are debugging to another
  74 program; if you attempt this, GDB is likely to wind up debugging the
  75 wrong program.
  76 </dl>
  77
  78    <p>When you issue the <code>run</code> command, your program begins to execute
  79 immediately.  See <a href="Stopping.html#Stopping">Stopping and continuing</a>, for discussion
  80 of how to arrange for your program to stop.  Once your program has
  81 stopped, you may call functions in your program, using the <code>print</code>
  82 or <code>call</code> commands.  See <a href="Data.html#Data">Examining Data</a>.
  83
  84    <p>If the modification time of your symbol file has changed since the last
  85 time GDB read its symbols, GDB discards its symbol
  86 table, and reads it again.  When it does this, GDB tries to retain
  87 your current breakpoints.
  88
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