C++ cli subcommands (with tclap) - c++

I'm using tclap for my cli program. How can I add subcommands with different parameters like for example in git?
The usage should be
./program cmd1 <name> [email]
./program --verbose cmd2 [-p <number>]
Also flags for all subcommands (like the --verbose) should be possible.
If it's not possible with tclap, what would you suggest else?

This isn't really part of the design of TCLAP. It's focused on providing "POSIX style" command line flags/arguments, which was the style of the day. It would probably not be too difficult to provide a git-style parser in the same spirit of TCLAP, but as of now TCLAP is probably to wrong tool for the job.

Related

organising Fabric's command list output

I have a Fabric fabfile.py with a long list of commands (and growing). When I go fab -l I can't see the top of the command list. Grouping the commands under headers wouldn't make the list any shorter but it would make skimming the list easier - rather like the output of Django's ./manage.py help command. Has anyone solved this problem?
Using Fabric's "new style" tasks, you can take advantage of namespaces. When you list your tasks, you can provide the -F (--list-format) argument, providing nested as the value, which will list the available tasks in a nested fashion, by namespace, the appearance of such is documented here.
Fabric's "nested" task listing isn't quite as neat looking as Django's management command separation that lists commands by app in a very neat fashion, but it's a start.

Up arrow based command history in console input (C++)

I am trying to build a console application that takes user input. I was able to use printf to keep the cursor in the same place, I could have used curses as well, but I can't get up-arrow command history to work. Any pointers ?
I think you want readline (www.gnu.org/software/readline/ which seems to now redirect to the maintainer site at http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html)
In addition to the mentions of the readline library, I'll also mention the BSD-licensed editline library and the rlwrap command-line wrapper tool that runs any program with a readline-based history.
As long as the GNU license is not a problem for you, I would strongly consider GNU Readline
Have a look at the GNU Readline library. It can provide input history support.
In Windows the standard console windows provide up-arrow input history -- you don't have to do anything. For other standard Windows console services see the doskey command quickhelp, and simply replace the word "command" with "line of input". It's a bit misleading, yes.
EDIT, added para: Possibly you're doing something that circumvents the standard services. I just noticed that the browser window title says "ncurses", which is not in your current question title. Perhaps that's it, but in that case, ask specifically for help with ncurses.
For *nix see the other answers.
Cheers & hth.

Simple interactive prompt in C++

I work on an application that usually runs unattended. Now I need to add to it something like an interactive prompt. In the interactive mode the operator will be able to give simple commands to the application - nothing fancy, simple commands like start and stop. Parametrized commands (e.g. repeat 10) and commands history could be nice too.
Do you know, by chance, any library that helps with such tasks. I've been thinking about something that works like boost::program_options or gflags but for an interactive prompt and not for command line parameters. Any ideas?
Thanks
Readline is one the best known libraries for this
http://tiswww.case.edu/php/chet/readline/rltop.html
It is covered by GPL, so it is only possible to use in GPL-compatible programs.
I did a quick search for alternatives, and found this:
http://github.com/antirez/linenoise
I'm not sure if the following is a reasonable amount of work for what you're trying to do, but Python has a very nice Command Line Interface (CLI) building library called cmd2. If it's possible to expose the relevant parts of your apps to Python using SWIG or CTypes, then doing the rest should be easy.
Here's a nice video presentation about cmd2:
PyCon 2010:Easy command-line applications with cmd and cmd2
HTH
One possibilty is to open a TCP port and accept messages in text format. Then you can telnet to that port and issue simple commands.

Is it possible to customize the indent style of XCode?

For example, I'd like to not indent namespaces in C++ code, but the prefpane doesn't seem to have any place to make a decision of this granularity. Is there some hidden config file or something? Or am I just out of luck?
Apple's XCode documentation contains a full list of user preferences, many of them that don't have a corresponding UI. I'm not seeing anything that is namespace-specific however, so I think you might be out of luck.
However, I thought I'd pass along the preferences list in case it's useful.
I've also attempted to do this.
The answer is that whoever did the code formatting in XCode appears to be completely unaware that there are languages other than Objective C, or coding styles other than Apple's.
Here's a list of things that one would want to do that can't be done in XCode.
Indent public: or private: just one space.
Indent namespaces zero spaces.
Alternate indentation for arguments NOT relative to the opening parenthesis.
The last one needs a little discussion. Sometimes, a function or method name can be quite long, as well as its first argument, so you want also to be able to indent like this:
someExcitingClass->AVeryLongMethodNameTraLaLaLaLa(
someLongExpressionOrVariableNameGoesHere,
anotherNameHere);
Of course, you might want to be extracting subexpressions to make the line shorter, but in real-world code this comes up all the time, and creating subexpressions just to fit everything into a reasonable line length is annoying.
It's a terrible shame and I really have no idea what to do. I personally write in emacs and only dip into XCode as a build system but :-D that's not for everyone.
As the Xcode indenter uses just the lexer, and not the AST, you can 'fool' the formatting by defining away the curly braces.
I have:
#define NAMESPACE_OPEN(_name) namespace _name {
#define NAMESPACE_CLOSE(_name) }
#define dsmsg_namespace_open NAMESPACE_OPEN(dsmsg)
#define dsmsg_namespace_close NAMESPACE_CLOSE(dsmsg)
i.e., a generic 'NAMESPACE_OPEN/CLOSE' define, and a define specific to my most-used namespace 'dsmsg'. Then, whenever I want to open the namespace, I use
dsmsg_namespace_open
... code ...
dsmsg_namespace_close
Ugly hack, but I quite like having a specific, named 'close'
I bypass Xcode's indenting altogether, and have a user script that calls uncrustify on the currently displayed document.
#!/bin/sh
#echo -n "%%%{PBXSelection}%%%"
uncrustify -q -c ~/.uncrustify/sample.cfg -l oc+
#echo -n "%%%{PBXSelection}%%%"
Notes:
uncrustify must be in your PATH
you may need to adjust the location of your config file
if you want to have the new code selected in Xcode, uncomment the two echo statements (this can also be used to make a "Format Selection" script, rather than "Format All"
Script Settings:
Input:Entire Document
Directory: Home directory
Output: Replace Document Contents
Errors: display in alert
As of Xcode 4.3.1 no custom namespace indent options are available, however I overcame this irritation by navigating to Preferences->Text Editing->Indentation and disabling "Syntax-aware indenting".
Another possibility is to use Articstic Style (astyle). A tutorial how to integrate astyle into XCode using automator and services can be found here: http://eatmyrandom.blogspot.com/2011/03/xcode-astyle-part-2-for-xcode-4x.html and http://youtu.be/d8bbE6_OHGc

How to highlight and color gdb output during interactive debugging?

Please don't reply I should use ddd, nemiver, emacs, vim, or any other front-end, I just prefer gdb as it is, but would like to see its output with some terminal colors.
.gdbinit
You can tweak your ~/.gdbinit to have colors. You can use mammon's .gdbinit which is available here:
https://github.com/gdbinit/gdbinit
You can tweak it as much as you want too. I found this thanks to this SO answer. Here's the kind of output that you can obtain:
A GitHub repository is also available: https://github.com/gdbinit/Gdbinit
On a side note, the same idea was also applied to lldb.
GDB Dashboard
Following the same concept, GDB Dashboard provides a modular visual interface for GDB in Python.
(void)walker
Another similar project uses GDB's Python support to provide more extensibility, so this is worth checking out: https://github.com/dholm/voidwalker
#dholm also provides his own .gdbinit inspired from the previous one.
pwndbg
Some projects provide a set of useful functions, including improved display. This is the case for PEDA or pwndbg. The latter gives the following description:
A PEDA replacement. In the spirit of our good friend windbg, pwndbg is pronounced pwnd-bag.
Speed
Resiliency
Clean code
It provides commands to support debugging and exploit development similar to the ones from PEDA, and better display (although this is not the main focus of the project). The software is still under development, and has not been properly released yet.
voltron
The project description states:
Voltron is an extensible debugger UI for hackers. It allows you to
attach utility views running in other terminals to your debugger (LLDB
or GDB), displaying helpful information such as disassembly, stack
contents, register values, etc, while still giving you the same
debugger CLI you're used to.
You can modify your .gdbinit to automatically integrate it. However, the display itself is outside of GDB (e.g. in a tmux split).
GEF
GEF is another option, and it is described as:
It is aimed to be used mostly by exploiters and reverse-engineers, to
provide additional features to GDB using the Python API to assist
during the process of dynamic analysis and exploit development.
It's not colours, but consider gdb's text gui. It makes a vast difference to how usable gdb is.
You can launch it with:
gdb -tui executable.out
Screenshot:
As you can see, the main features are:
shows what line of the source we are on and surrounding lines
shows breakpoints
I know you did not want a frontend.
But how about cgdb it is very close to gdb,
it is textmode but has a source window above with syntax highlight on the code.
New in upcoming GDB 8.3!
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=gdb/NEWS
Terminal styling is now available for the CLI and the TUI. GNU Source
Highlight can additionally be used to provide styling of source code
snippets. See the "set style" commands, below, for more information.
It is possible to greatly enhance the appears of gdb through the use of colors. This is done via any of the following methods:
Colorized prompt via the "set prompt". E.g., make the prompt bold and red:
set prompt \033[1;31m(gdb) \033[m
or make the prompt a new shape, bold and red:
set prompt \033[01;31m\n\n#####################################> \033[0m
Colorized commands via hooks
Colorized syntax highlighting of the "list" command.
All examples are available at the following blog posts written by Michael Kelleher:
"Beautify GDB", May 12, 2010 (via archive.org)
"Experimental GDB syntax highlighting", May 15, 2010 (via archive.org)
cgdb is much better than gdb -tui
#into .gdbinit
shell mkfifo /tmp/colorPipe
define hook-disassemble
echo \n
shell cat /tmp/colorPipe | c++filt | highlight --syntax=asm -s darkness -Oxterm256 &
set logging redirect on
set logging on /tmp/colorPipe
end
define hookpost-disassemble
hookpost-list
end
define hook-list
echo \n
shell cat /tmp/colorPipe | c++filt | highlight --syntax=cpp -s darkness -Oxterm256 &
set logging redirect on
set logging on /tmp/colorPipe
end
define hookpost-list
set logging off
set logging redirect off
shell sleep 0.1s
end
define hook-quit
shell rm /tmp/colorPipe
end
define re
hookpost-disassemble
echo \033[0m
end
document re
Restore colorscheme
end
Warning: Buggy. No TUI support, 'user-mode' hack.
Found the main part here
and modified it a bit. Needs highlight, c++filt. If colors get messed up issue re command.
Neat, I just found this hack using colout: https://github.com/nojhan/colout/blob/master/colout/example.gdbinit
I wanted to highlight as follows: emphasise the lines of a stack trace which belong to my source files (rather than libraries).
The solution was to use gdb-python (on MSYS; on Linux typically gdb comes with Python built-in already?), hook backtrace, use
python stack_trace = gdb.execute('backtrace', False, True')
Then process stack_trace with Python's regexes, and print them out. Bold and other colours are achieved by a function like this:
def term_style(*v):
"""1 is bold, 30--37 are the 8 colours, but specifying bold may also
change the colour. 40--47 are background colours."""
return '\x1B['+';'.join(map(str, v))+'m'
#Use like this:
print term_style(1) + 'This will be bold' + term_style(0) #Reset.
print term_style(1,30) + 'This will be bold and coloured' + term_style(0)
print term_style(1,30,40) + 'Plus coloured background' + term_style(0)
Another good combination of colors is given by this configuration. It renders inspecting the backtraces a lot easier. To use it, just save that file as ~/.gdbinit and run gdb normally
you can get whatever colors you want;
# gdb
(gdb) shell echo -en '\E[47;34m'"\033[1m"
...
anything is now blue foreground and white background
...
(gdb) shell tput sgr0
... back to normal