See [here.][1] In short you should do:

	
    p *array@len

  [1]: https://sourceware.org/gdb/current/onlinedocs/gdb/Arrays.html


`*(T (*)[N])p` where T is the type, N is the number of elements and p is the pointer.

Use the `x` command.

    (gdb) x/100w a


### How to view or print _any number of bytes_ from _any array_ in _any `printf`-style format_ using the `gdb` debugger

As [@Ivaylo Strandjev says here][1], the general syntax is:

```bash
print *my_array@len
# OR the shorter version:
p *my_array@len
```

Example to print the first 10 bytes from `my_array`:

```bash
print *my_array@10
```

**[Recommended!] Custom `printf`-style print formatting:** however, if the commands above look like garbage since it tries to interpret the values as chars, you can force different formatting options like this:

1. `print/x *my_array@10` = hex
1. `print/d *my_array@10` = signed integer
1. `print/u *my_array@10` = unsigned integer
1. `print/&lt;format&gt; *my_array@10` = print according to the general [`printf()`-style format string][2], `&lt;format&gt;`

Here are some real examples from my debugger to print 16 bytes from a `uint8_t` array named `byteArray`. Notice how ugly the first one is, with just `p *byteArray@16`:

```bash
(gdb) p *byteArray@16
$4 = &quot;\000\001\002\003\004\005\006\a\370\371\372\373\374\375\376\377&quot;

(gdb) print/x *byteArray@16
$5 = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff}

(gdb) print/d *byteArray@16
$6 = {0, 1, 2, 3, 4, 5, 6, 7, -8, -7, -6, -5, -4, -3, -2, -1}

(gdb) print/u *byteArray@16
$7 = {0, 1, 2, 3, 4, 5, 6, 7, 248, 249, 250, 251, 252, 253, 254, 255}
```

In my case, the best version, with the correct representation I want to see, is the last one where I print the array as unsigned integers using `print/u`, since it is a `uint8_t` unsigned integer array after-all:

```bash
(gdb) print/u *byteArray@16
$7 = {0, 1, 2, 3, 4, 5, 6, 7, 248, 249, 250, 251, 252, 253, 254, 255}
```


  [1]: https://stackoverflow.com/a/14502287/4561887
  [2]: http://www.cplusplus.com/reference/cstdio/printf/

`(int[100])*pointer` worked for me thanks to suggestion in the comments by @Ruslan 

    &lt;a href=&quot;#/search?query={{address}}&quot; ng-repeat=&quot;address in addresses&quot;&gt;
      {{address}}
    &lt;/a&gt;

generates links that are not url encoded if I understand correctly. What is the proper way to encode `#/search?query={{address}}`?

Example address is `1260 6th Ave, New York, NY`.

How to generate url encoded anchor links with AngularJS?

I have a `ScheduledExecutorService` that times a few different task periodically with `scheduleAtFixedRate(Runnable, INIT_DELAY, ACTION_DELAY, TimeUnit.SECONDS);`

I also have a different `Runnable` that I&#39;m using with this scheduler.
the problem starts when I want to remove one of the tasks from the scheduler.

Is there a way to do this?

Am I doing the right thing using one scheduler for different tasks?
What is the best way to implement this?



How to remove a task from ScheduledExecutorService?

Suppose defined: `int a[100]`  Type `print a` then gdb will automatically display it as an array:`1, 2, 3, 4...`. However, if `a` is passed to a function as a parameter, then gdb will treat it as a normal int pointer, type `print a` will display:`(int *)0x7fffffffdaa0`. What should I do if I want to view `a` as an array?

How to view a pointer like an array in GDB?

<p>Suppose defined: <code>int a[100]</code>  Type <code>print a</code> then gdb will automatically display it as an array:<code>1, 2, 3, 4...</code>. However, if <code>a</code> is passed to a function as a parameter, then gdb will treat it as a normal int pointer, type <code>print a</code> will display:<code>(int *)0x7fffffffdaa0</code>. What should I do if I want to view <code>a</code> as an array?</p>


I came across the data type `int32_t` in a C program recently.  I know that it stores 32 bits, but don&#39;t `int` and `int32` do the same?

Also, I want to use `char` in a program.  Can I use `int8_t` instead? What is the difference?

To summarize: **what is the difference between int32, int, int32_t, int8 and int8_t in C?**

Difference between int32, int, int32_t, int8 and int8_t

I&#39;m writing a console program in C++ to download a large file. I know the file size, and I start a work thread to download it. I want to show a progress indicator to make it look cooler.

How can I display different strings at different times, but at the same position, in cout or printf?

How to display a progress indicator in pure C/C++ (cout/printf)?

I saw an interesting technique used in an [answer][1] to [another question][2], and would like to understand it a little better.

We&#39;re given an unsigned 64-bit integer, and we are interested in the following bits:

    1.......2.......3.......4.......5.......6.......7.......8.......

Specifically, we&#39;d like to move them to the top eight positions, like so:

    12345678........................................................

We don&#39;t care about the value of the bits indicated by `.`, and they don&#39;t have to be preserved.

The [solution][1] was to mask out the unwanted bits, and multiply the result by `0x2040810204081`. This, as it turns out, does the trick.

How general is this method? Can this technique be used to extract any subset of bits? If not, how does one figure out whether or not the method works for a particular set of bits?

Finally, how would one go about finding the (a?) correct multiplier to extract the given bits?

  [1]: https://stackoverflow.com/a/14539116/367273
  [2]: https://stackoverflow.com/questions/14537831/isolate-specific-row-column-diagonal-from-a-64-bit-number

Extracting bits with a single multiplication

By considering that the memory is divided into four segments: data, heap, stack, and code, where do global variables, static variables, constant data types, local variables (defined and declared in functions), variables (in main function), pointers, and dynamically allocated space (using malloc and calloc) get stored in memory?

I think they would be allocated as follows:

- Global variables  -------&gt;  data
- Static variables  -------&gt;  data
- Constant data types -----&gt;  code
- Local variables (declared and defined in functions)  --------&gt;  stack
- Variables declared and defined in main function  -----&gt;  heap
- Pointers (for example, `char *arr`, `int *arr`) -------&gt;  heap
- Dynamically allocated space (using malloc and calloc) --------&gt; stack

I am referring to these variables only from the C perspective.

Please correct me if I am wrong as I am new to C.


Where in memory are my variables stored in C?

In C, let&#39;s say you have a variable called `variable_name`. Let&#39;s say it&#39;s located at `0xaaaaaaaa`, and at that memory address, you have the integer 123. So in other words, `variable_name` contains 123.

I&#39;m looking for clarification around the phrasing &quot;`variable_name` is located at `0xaaaaaaaa`&quot;. How does the compiler recognize that the string &quot;variable_name&quot; is associated with that particular memory address? Is the string &quot;variable_name&quot; stored somewhere in memory? Does the compiler just substitute `variable_name` for `0xaaaaaaaa` whenever it sees it, and if so, wouldn&#39;t it have to use memory in order to make that substitution?


How are variable names stored in memory in C?

`list` commands prints a set of lines, but I need one single line, where I am and where an error has probably occurred.



gdb: how to print the current line or find the current line number?

At some point during my work, Xcode&#39;s `po` and `p` commands stopped working. No matter what I enter, it doesn&#39;t generate output:

    (gdb) po self
    (gdb) po [self name]
    (gdb) po [UITableView class]
    (gdb) po @&quot;Hello&quot;
    (gdb) p indexPath.row
    (gdb) print indexPath.row
    (gdb) po fjkldsjflksdjklwjfkljfkldsjflk
    (gdb)

When I enter any of these commands, the command line just goes to the next line, where it prints the blue `(gdb)`, but no output.

I tried the following steps:

- Restart Xcode, restart my Macbook
- Tried while debugging in the simulator as well as on a iOS device
- Switched to LLDB and restarted
- Re-installed Xcode

The other debugging tools in Xcode seem to work okay: Breakpoints, step-by-step execution, the **Auto** variable examination window etc.

**Any ideas?**

**EDIT:** Doesn&#39;t work even after a re-install of Xcode.


po command in Xcode does not generate output

In gdb, after reaching a breakpoint, I want to list all the variables in the current context, instead of giving each variable name explicitly? Is there any way to achieve this at all?

How to list all variables in the current context in gdb?

Is there an equivalent command in GDB to that of WinDbg&#39;s `!process 0 7`?

I want to extract all the threads in a dump file along with their backtraces in GDB. `info threads` doesn&#39;t output the stack traces. So, is there a command that does?


How do I get the backtrace for all the threads in GDB?

I&#39;m under osx 10.8.4 and have installed gdb 7.5.1 with homebrew (motivation get a new gdb with  new features such as --with-python etc... )

Long story short when I run debug within a c++ Eclipse project I get :


    Error in final launch sequence
    Failed to execute MI command:
    -exec-run
    Error message from debugger back end:
    Unable to find Mach task port for process-id 46234: (os/kern) failure (0x5).
     (please check gdb is codesigned - see taskgated(8))
    Unable to find Mach task port for process-id 46234: (os/kern) failure (0x5).
     (please check gdb is codesigned - see taskgated(8))

I have followed various suggestions for code signing

- https://sourceware.org/gdb/wiki/BuildingOnDarwin
- partly http://www.noktec.be/archives/1251 with various adjusts

So I did:

1. Set up the certificate
2. Sign the gdb -&gt; codesign -s gdb-cert /usr/local/bin/gdb

When I re-run debugging in Eclipse I get same error as above &quot;(please check gdb is codesigned - see taskgated(8))&quot;.

If I set back the gdb to the older gdb (in the gdb preferences of Eclipse) /usr/libexec/gdb/gdb-i386-apple-darwin the debugging runs as expected.

Any solutions / hints out there ?

Thx

Pelle

Content Type	Original Author	Original Content on Stackoverflow
Question	CDT	View Question on Stackoverflow
Solution 1 - C	Ivaylo Strandjev	View Answer on Stackoverflow
Solution 2 - C	R.. GitHub STOP HELPING ICE	View Answer on Stackoverflow
Solution 3 - C	aschepler	View Answer on Stackoverflow
Solution 4 - C	Gabriel Staples	View Answer on Stackoverflow
Solution 5 - C	Ali80	View Answer on Stackoverflow

How to view a pointer like an array in GDB?

C Problem Overview

C Solutions

Solution 1 - C

Solution 2 - C

Solution 3 - C

Solution 4 - C

How to view or print any number of bytes from any array in any `printf`-style format using the `gdb` debugger

Solution 5 - C

How to remove a task from ScheduledExecutorService?

How to generate url encoded anchor links with AngularJS?

Attributions

C Problem Overview

C Solutions

Solution 1 - C

Solution 2 - C

Solution 3 - C

Solution 4 - C

How to view or print any number of bytes from any array in any printf-style format using the gdb debugger

Solution 5 - C

How to remove a task from ScheduledExecutorService?

How to generate url encoded anchor links with AngularJS?

Attributions

How to view or print any number of bytes from any array in any `printf`-style format using the `gdb` debugger