Free debugging software for linux

Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).
Charles can act as a man-in-the-middle for HTTP/SSL communication, enabling you to debug the content of your HTTPS sessions.
Charles simulates modem speeds by effectively throttling your bandwidth and introducing latency, so that you can experience an entire website as a modem user might (bandwidth simulator).
Charles is especially useful for Macromedia Flash developers as you can view the contents of LoadVariables, LoadMovie and XML loads. More about Charles and Flash.
Main features:
- Cookies are shown in the HTTP headers, so you can see exactly what cookies you are sending and receiving.
- Every request and response is recorded in Charles. Redirects that are often too quick to see when testing with a web browser can be seen in Charles. Requests from applications other than your web browser (such as Flash movies) can also be seen.
- Request and response sizes are shown in Charles, so you can see how big each request was.
- Assets loaded from an HTML page are recorded so that you can see how many images etc are loaded by a page, and where from.
- All files can be viewed, including JavaScript files, CSS files, HTML files etc.
- Mirror all responses to disk, recording your session.
- Blacklist sites so that requests are blocked.
- See the results of caching by seeing cached responses (304 Not Modified), and requests containing last modified dates (IfModifiedSince).
- Disable caching by removing cache related headers from requests and responses as they pass through Charles, ensuring that you are always requesting the latest file.
- See whether a cache has served your request by looking for cache-hit HTTP headers.
- View encrypted HTTPS/SSL data.
- View encrypted HTTPS traffic in plain text. Enables you to view requests and responses in plain text even when communicating with an SSL secured web server.
- Reveal unexpected requests, such as typos and 404s.
- View requested images.
- Throttle your web connection to a specified bytes/second speed, and millisecond latency. This enables you to simulate modem conditions on a high speed internet connection (bandwidth simulator)
- Spoof DNS name to ip mappings so that you can test a domain name before it has gone live. Very useful for testing your virtual hosting.
- Export to CSV all of the summary data captured by Charles for analysis and reporting in Excel
- Reverse proxy creates ports on the localhost that act as regular HTTP servers, but forward all requests to a specified web server.
- HTTP/1.1 support - including keep-alive, chunking and content-encodings including gzip, compress and deflate.
- External proxy support - configure an proxy for Charles to use to access the Internet
- NTLM authentication support (Windows NT Challenge Response Authentication / Integrated Windows Authentication)
- Automatic configuration of Windows Internet Proxy settings.
- Search all headers and bodies for keywords.
- Transparent forwarding support, allows any protocol to be forwarded by Charles and debugged.
- Unicode and other charset encoding/decoding support.

Libcwd is a full-featured and well-documented library that assists C++ developers with debugging their applications.
C++ Debugging Support library includes support for ostream-based debug output, custom debug channels and devices, memory allocation debugging, run-time sourcefile:linenumber information, and demangled type names of variables. It is thread-safe.
Main features:
- End-users of an application dont need to install libcwd.
- The use of namespaces prevents name collisions between debug channels of different libraries.
- Debug channels and devices can be turned on or off on a per thread basis.
- All debug code can be omitted from the executable by not defining a single CWDEBUG macro.
- Code using libcwd looks clean and is surveyable as a result of using a few well-defined macros, avoiding the need of disturbing #ifdef CWDEBUG ... #endif constructs.
- Debug output is written to an ostream and as such type-safe and customizable as is usual for C++ ostreams.
- An arbitrary number of debug channels and debug devices can be created without any penalty in terms of cpu usage.
- Full support for all forms of iterative and recursive calls.
- Debug output is surveyable as a result of several possibilities to format the output, like a margin string, a marker string, indentation and fixed-width channel labels. All formatting is thread specific.
- Printing the type of arbitrary variables in demangled form.
- Printing addresses in source file:line number presentation.
- Deallocation pointer validation.
- Magic numbers around allocated memory blocks in order to detect buffer overruns.
- Printing an overview of current memory allocations, including start address, size, type of allocated object, source file and line number of allocation and a user definable description.
- Finding allocation information with only a pointer that points inside an allocated memory block, in logarithmic time.
Enhancements:
- This release adds support for x86_64.

Xdebug project is an extension that helps you debugging your script by providing a lot of valuable debug information. The debug information that Xdebug can provide includes the following:
- stack and function traces in error messages with:
- full parameter display for user defined functions
- function name, file name and line indications
- support for member functions
- memory allocation
- protection for infinite recursions
Xdebug also provides:
- profiling information for PHP scripts
- script execution analysis
- capabilities to debug your scripts interactively with a debug client

Debug::Trace is a Perl extension to trace subroutine calls.

SYNOPSIS

perl -MDebug::Trace=foo,bar yourprogram.pl

Debug::Trace instruments subroutines to provide tracing information upon every call and return.

Using Debug::Trace does not require any changes to your sources. Most often, it will be used from the command line:

perl -MDebug::Trace=foo,bar yourprogram.pl

This will have your subroutines foo() and bar() printing call and return information.

Subroutine names may be fully qualified to denote subroutines in other packages than the default main::.

By default, the trace information is output using the standard warn() function.

MODIFIERS

Modifiers can be inserted in the list of subroutines to change the default behavior of this module. All modifiers can be used in three ways:

:name to enable a specific feature.
:noname to disable a specific feature.
:name(value) to set a feature to a specific value. In general, :name is equivalent to :name(1), while :noname corresponds to :name(0).

The following modifiers are recognized:

:warn

Uses warn() to produce the trace output (default). :nowarn Sends trace output directly to STDERR.

:caller

Add basic call information to the trace message, including from where the routine was called, and by whom. This is enabled by default.

:stacktrace

Add a stack trace (call history).

:maxlen(length)

Truncate the length of the lines of trace information to length characters.

The following modifiers can be used to control the way Data::Dumper prints the values of parameters and return values. See also Data::Dumper.

:indent

Controls the style of indentation. It can be set to 0, 1, 2 or 3. Style 0 spews output without any newlines, indentation, or spaces between list items. :indent(0) is the default.

:useqq

When enabled, uses double quotes for representing string values. Whitespace other than space will be represented as [ntr], "unsafe" characters will be backslashed, and unprintable characters will be output as quoted octal integers. This is the default, use :nouseqq to disable.

:maxdepth(depth)

Can be set to a positive integer that specifies the depth beyond which which we dont print structure contents. The default is 2, which means one level of array/hashes in argument lists and return values is expanded. If you use :nomaxdepth or :maxdepth(0), nested structures are fully expanded.

:quotekeys

Controls wether hash keys are always printed quoted. The default is :noquotekeys.

sortkeys

Controls whether hash keys are dumped in sorted order. The default is :nosortkeys.

Modifiers apply only to the subroutines that follow in the list of arguments.

Bash Debugger project contains patched sources to BASH that enable better debugging support as well as improved error reporting.
In addition, this project contains the most comprehensive source-code debugger for bash that has been written.
Since this project maintains as an open CVS development and encourages developers and ideas, the space could be also be used springboard for other experiments and additions to BASH.
Enhancements:
- This release adds a gdb-like "load" command to force reading in a file.
- Files coming from function line-specifications are now read in (Debian Bug #40336).
- Negative numbers are now allowed in "frame" (and "up" and "down") commands.
- Help, manual page, and documentation fixes have been made, including suggested use of $PS4.

Brainfuck Debugger is designed to encourage the development of Brainfuck programs by providing an IDE with debugging features.

One of the goals of this project is to provide an environment for people who want to experiment with the fundimental processes of computers, but not get blown away with complicated syntax issues.

Logging Services project is intended to provide cross-language logging services for purposes of application debugging and auditing.
We should also mention that thanks to the relentless efforts of many developers, we have a basic level of interoperability between the following projects:
- Log4Cxx (c++)
- Log4j
- Log4Net
- Log4Perl
- Log4PHP
- Log4PLSQL
- JDK1.4s util.logging framework
There is still much work ahead bringing in the various projects to work together within the Logging Services Project. The process is likely to take a little while. In the mean time, we will continue to do what we like best, that is developing open source software.
This is a project of the Apache Software Foundation (ASF). Like all Apache projects, we encourage a collaborative, consensus-based development process. We offer an open and pragmatic software license, and we strive to create software of the highest quality. The ASF is organized into several projects, which like Logging Services project may contain multiple sub-projects.

gnscd is a name service caching daemon. gnscd is a replacement for nscd that has been rewritten with different networking and database code. It implements both the glibc235 and glibc232 nscd protocols in one daemon, sharing one cache.

OPTIONS

-g

Display basic information on daemon status. For compatibility with GNU nscd. Useful in watchdog scripts.

-d

Dont daemonize. Also print debugging information about what is going on inside gnscd