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| <h3 class="section">8.5 Applying a Command to Several Frames.</h3> |
| |
| <p><a name="index-frame-apply-545"></a><a name="index-apply-command-to-several-frames-546"></a> |
| <dl> |
| <dt><code>frame apply [all | </code><var>count</var><code> | </code><var>-count</var><code> | level </code><var>level</var><code>...] [</code><var>flag</var><code>]... </code><var>command</var><dd>The <code>frame apply</code> command allows you to apply the named |
| <var>command</var> to one or more frames. |
| |
| <dl> |
| <dt><code>all</code><dd>Specify <code>all</code> to apply <var>command</var> to all frames. |
| |
| <br><dt><var>count</var><dd>Use <var>count</var> to apply <var>command</var> to the innermost <var>count</var> |
| frames, where <var>count</var> is a positive number. |
| |
| <br><dt><var>-count</var><dd>Use <var>-count</var> to apply <var>command</var> to the outermost <var>count</var> |
| frames, where <var>count</var> is a positive number. |
| |
| <br><dt><code>level</code><dd>Use <code>level</code> to apply <var>command</var> to the set of frames identified |
| by the <var>level</var> list. <var>level</var> is a frame level or a range of frame |
| levels as <var>level1</var>-<var>level2</var>. The frame level is the number shown |
| in the first field of the ‘<samp><span class="samp">backtrace</span></samp>’ command output. |
| E.g., ‘<samp><span class="samp">2-4 6-8 3</span></samp>’ indicates to apply <var>command</var> for the frames |
| at levels 2, 3, 4, 6, 7, 8, and then again on frame at level 3. |
| |
| </dl> |
| |
| </dl> |
| |
| <p>Note that the frames on which <code>frame apply</code> applies a command are |
| also influenced by the <code>set backtrace</code> settings such as <code>set |
| backtrace past-main</code> and <code>set backtrace limit N</code>. See |
| See <a href="Backtrace.html#Backtrace">Backtraces</a>. |
| |
| <p>The <var>flag</var> arguments control what output to produce and how to handle |
| errors raised when applying <var>command</var> to a frame. <var>flag</var> |
| must start with a <code>-</code> directly followed by one letter in |
| <code>qcs</code>. If several flags are provided, they must be given |
| individually, such as <code>-c -q</code>. |
| |
| <p>By default, <span class="sc">gdb</span> displays some frame information before the |
| output produced by <var>command</var>, and an error raised during the |
| execution of a <var>command</var> will abort <code>frame apply</code>. The |
| following flags can be used to fine-tune this behavior: |
| |
| <dl> |
| <dt><code>-c</code><dd>The flag <code>-c</code>, which stands for ‘<samp><span class="samp">continue</span></samp>’, causes any |
| errors in <var>command</var> to be displayed, and the execution of |
| <code>frame apply</code> then continues. |
| <br><dt><code>-s</code><dd>The flag <code>-s</code>, which stands for ‘<samp><span class="samp">silent</span></samp>’, causes any errors |
| or empty output produced by a <var>command</var> to be silently ignored. |
| That is, the execution continues, but the frame information and errors |
| are not printed. |
| <br><dt><code>-q</code><dd>The flag <code>-q</code> (‘<samp><span class="samp">quiet</span></samp>’) disables printing the frame |
| information. |
| </dl> |
| |
| <p>The following example shows how the flags <code>-c</code> and <code>-s</code> are |
| working when applying the command <code>p j</code> to all frames, where |
| variable <code>j</code> can only be successfully printed in the outermost |
| <code>#1 main</code> frame. |
| |
| <pre class="smallexample"> (gdb) frame apply all p j |
| #0 some_function (i=5) at fun.c:4 |
| No symbol "j" in current context. |
| (gdb) frame apply all -c p j |
| #0 some_function (i=5) at fun.c:4 |
| No symbol "j" in current context. |
| #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 |
| $1 = 5 |
| (gdb) frame apply all -s p j |
| #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 |
| $2 = 5 |
| (gdb) |
| </pre> |
| <p>By default, ‘<samp><span class="samp">frame apply</span></samp>’, prints the frame location |
| information before the command output: |
| |
| <pre class="smallexample"> (gdb) frame apply all p $sp |
| #0 some_function (i=5) at fun.c:4 |
| $4 = (void *) 0xffffd1e0 |
| #1 0x565555fb in main (argc=1, argv=0xffffd2c4) at fun.c:11 |
| $5 = (void *) 0xffffd1f0 |
| (gdb) |
| </pre> |
| <p>If flag <code>-q</code> is given, no frame information is printed: |
| <pre class="smallexample"> (gdb) frame apply all -q p $sp |
| $12 = (void *) 0xffffd1e0 |
| $13 = (void *) 0xffffd1f0 |
| (gdb) |
| </pre> |
| |
| <a name="index-faas-547"></a> |
| <a name="index-apply-a-command-to-all-frames-_0028ignoring-errors-and-empty-output_0029-548"></a> |
| <dl><dt><code>faas </code><var>command</var><dd>Shortcut for <code>frame apply all -s </code><var>command</var>. |
| Applies <var>command</var> on all frames, ignoring errors and empty output. |
| |
| <p>It can for example be used to print a local variable or a function |
| argument without knowing the frame where this variable or argument |
| is, using: |
| <pre class="smallexample"> (gdb) faas p some_local_var_i_do_not_remember_where_it_is |
| </pre> |
| <p>Note that the command <code>tfaas </code><var>command</var> applies <var>command</var> |
| on all frames of all threads. See See <a href="Threads.html#Threads">Threads</a>. |
| </dl> |
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