Free log software for linux

dclog is a logging library for C and C++. It supports the concept of log levels, configurable logfile timestamps, and a configurable prefix to log messages.

Installation:

1. From source:

make all
make install (as root)

2. Gentoo users:

emerge -vp dclog
emerge dclog

klogview is a KDE real-time log file viewer, like tail -f. The main window contains any number of dockable log panels, with an arbitrary number of log sources in each of them.
Every log source can have a separate font color and style. Other features include filters, alerts, different encodings, and tray support.
Main features:
- Any number of dockable log panels
- Any number of log sources per log panel
- "File" log source
- "Process output" log source
- Configurable fonts and colors
- Filters and alerts
- Tray icon
Enhancements:
- Removed forced autoscroll
- Ability to reopen log files
- Ability to enable/disable log sources stop filter flag

Snowlog is a webserver access log browser/analyzer. It does not generate static reports, but lets you browse through the requests in real time. Filters that accept regular expressions can be applied.

Installation:

make
make install (as root)

Simple Log is a small library that does logging very simply and requires you to do almost nothing (other than actually logging) to get log output to happen. Simple Log is much simpler to use than a logging framework, especially in terms of configuration.
It doesnt attempt to solve every logging problem in one package, but contains enough features to be a viable alternative for most applications that need logging. This tool will handle the logging needs of most small- to large-sized projects, but with an almost non-existent learning curve.
Enhancements:
- This release is primarily about the addition of log rolling (by time of day, file size, or custom strategy), the inclusion of a small but humorous user guide, the fixing of a raft of minor bugs, and the inclusion of a few other small features increasing flexibility.

Wiggly-Log is a small C++ logging library.
Whilst playing with graphics I found I needed a simple and fast logging implementation that I could improve as I needed.
I wanted to be able to use standard C++ features like streams for outputting user-defined datatypes instead of having to bother with C-style printf or other variadic functions.
I also wanted to be able to remove logging from certain very time sensitive parts completely at compile-time.
I had tried to find a logging package in C++ that was stable on both Linux and Windows but failed. Log4cpp looks to be orphaned and the code wasnt inspiring enough for me to want to try and mess with it.
Installation:
This package uses GNU automake and provides a configure script so you should be able to do the following:
bash$ ./configure
bash$ make
bash$ make install
If any of this doesnt work for you then get in touch, I have only built this on two platforms currently.
Enhancements:
- This release adds formatting classes: a simple XML formatter (just for testing) and a simple printf-like formatter.

Log::StdLog is a Perl module with a simple log file via a special filehandle.

SYNOPSIS

use Log::StdLog { level => warn, file => "$0.log" };

# Messages at the same or a higher level are logged...
print {*STDLOG} error => "This error message will be loggedn";
print {*STDLOG} warn => "This warning message will be loggedn";

# Messages at a lower level are ignored...
print {*STDLOG} info => "This info message will NOT be loggedn";

# The default message level is the one that was specified
# when the module was loaded...

print {*STDLOG} "This is a warning message. It will be loggedn";

This module provides a very simple kind of log file, with a very simple interface. Messages are logged simply by printing to *STDLOG, which the module exports to any namespace into which its loaded.

This patch can be used on a masquerading firewall (NAT) to keep a log of all the outgoing masqueraded TCP connections.
Its even possible to log the name of the user who has opened the connection. This can be a useful security tool for many small networks that are hidden by a masquerading box if users cannot be totally trusted. It can be used with linux 2.2.17, 2.2.19, 2.2.20 and maybe other (future) 2.2.x versions.
With this information you can know, in the above scenario, that the connection masquerader.yourdomain.com:666 [-3-] ==> crackme.victim.com:31337 [-2-] was started by attacker.yourdomain.com [-1-] from port 1234.
Now please note that this is NOT enough: if attacker.yourdomain.com is a multiuser machine at that time there could be 100 users logged in. Moreover a malicious user could attack crackme.victim.com from attacker.yourdomain.com even without being logged in (with either cron or with a background job or... etc.).
Since we dont want the users being able to hide themselves in this way, the masquerader makes a IDENT query to the client and, if IDENT is available, adds the response to the log together with [-1-], [-2-] and [-3-].
Its therefore recommended (although its optional) that you enable the IDENT service on all hosts on the internal network. Please note that if you restrict the IDENT service (e.g. with TCP wrappers) to the masquerader it wont work (exercise: can you understand why?). If your network configuration on the masquerader is OK, remote hosts wont be able to do IDENT queries (since they cant pass through the masquerader). Therefore allowing "everyone" to do IDENT queries on the clients should be safe enough. If you wish to allow remote hosts to do IDENT queries you can install a special IDENT server on the masquerade router, like pnidentd (for example).
Enhancements:
- Update for linux 2.2.19

Log Watcher is a tool for log watching and colorize.
Installation:
The `configure shell script attempts to guess correct values for various system-dependent variables used during compilation.
It uses those values to create a `Makefile in each directory of the package. It may also create one or more `.h files containing system-dependent definitions.
Finally, it creates a shell script `config.status that you can run in the future to recreate the current configuration, a file `config.cache that saves the results of its tests to speed up
reconfiguring, and a file `config.log containing compiler output (useful mainly for debugging `configure).
If you need to do unusual things to compile the package, please try to figure out how `configure could check whether to do them, and mail diffs or instructions to the address given in the `README so they can be considered for the next release.
If at some point `config.cache contains results you dont want to keep, you may remove or edit it.
The file `configure.in is used to create `configure by a program called `autoconf. You only need `configure.in if you want to change it or regenerate `configure using a newer version of `autoconf.
The simplest way to compile this package is:
1. `cd to the directory containing the packages source code and type `./configure to configure the package for your system.
If youre using `csh on an old version of System V, you might need to type `sh ./configure instead to prevent `csh from trying to execute `configure itself.
Running `configure takes awhile. While running, it prints some messages telling which features it is checking for.
2. Type `make to compile the package.
3. Optionally, type `make check to run any self-tests that come with the package.
4. Type `make install to install the programs and any data files and documentation.
5. You can remove the program binaries and object files from the source code directory by typing `make clean. To also remove the files that `configure created (so you can compile the package for a different kind of computer), type `make distclean.
There is also a `make maintainer-clean target, but that is intended mainly for the packages developers. If you use it, you may have to get all sorts of other programs in order to regenerate files that came with the distribution.
Enhancements:
- manual typos
- change defaults in config file
- minor changes needed to build on OpenBSD
- fixed lwatch crashes for some spurious configuration