1*458a6a73SNicolas Bonnefon 2*458a6a73SNicolas Bonnefon## Getting started 3*458a6a73SNicolas Bonnefon 4*458a6a73SNicolas Bonnefon_glogg_ can be started from the command line, optionally passing the file to 5*458a6a73SNicolas Bonnefonopen as an argument, or via the desktop environment's menu or file 6*458a6a73SNicolas Bonnefonassociation. 7*458a6a73SNicolas BonnefonIf no file name is passed, _glogg_ will initially open the last used file. 8*458a6a73SNicolas Bonnefon 9*458a6a73SNicolas BonnefonThe main window is divided in three parts : the top displays the log file. The 10*458a6a73SNicolas Bonnefonbottom part, called the "filtered view", shows the results of the search. The 11*458a6a73SNicolas Bonnefonline separating the two contains the regular expression used as a filter. 12*458a6a73SNicolas Bonnefon 13*458a6a73SNicolas BonnefonEntering a new regular expression, or a simple search term, will update the 14*458a6a73SNicolas Bonnefonbottom view, displaying the results of the search. The lines matching the 15*458a6a73SNicolas Bonnefonsearch criteria are listed in order in the results, and are marked with a red 16*458a6a73SNicolas Bonnefoncircle in both windows. 17*458a6a73SNicolas Bonnefon 18*458a6a73SNicolas Bonnefon## Exploring log files 19*458a6a73SNicolas Bonnefon 20*458a6a73SNicolas BonnefonRegular expressions are a powerful way to extract the information you are 21*458a6a73SNicolas Bonnefoninterested in from the log file. _glogg_ uses _extended regular expressions_. 22*458a6a73SNicolas Bonnefon 23*458a6a73SNicolas BonnefonOne of the most useful regexp feature when exploring logs is the 24*458a6a73SNicolas Bonnefon_alternation_, using parentheses and the | operator. It searches for several 25*458a6a73SNicolas Bonnefonalternatives, permitting to display several line types in the filtered window, 26*458a6a73SNicolas Bonnefonin the same order they appear in the log file. 27*458a6a73SNicolas Bonnefon 28*458a6a73SNicolas BonnefonFor example, to check that every connection opened is also closed, one can use 29*458a6a73SNicolas Bonnefonan expression similar to: 30*458a6a73SNicolas Bonnefon 31*458a6a73SNicolas Bonnefon`Entering (Open|Close)Connection` 32*458a6a73SNicolas Bonnefon 33*458a6a73SNicolas BonnefonAny 'open' call without a matching 'close' will immediately be obvious in the 34*458a6a73SNicolas Bonnefonfiltered window. 35*458a6a73SNicolas BonnefonThe alternation also works with the whole search line. For example if you also 36*458a6a73SNicolas Bonnefonwant to know what kind of connection has been opened: 37*458a6a73SNicolas Bonnefon 38*458a6a73SNicolas Bonnefon`Entering (Open|Close)Connection|Created a .* connection` 39*458a6a73SNicolas Bonnefon 40*458a6a73SNicolas Bonnefon`.*` will match any sequence of character on a single line, but _glogg_ will only 41*458a6a73SNicolas Bonnefondisplay lines with a space and the word `connection` somewhere after `Created a` 42*458a6a73SNicolas Bonnefon 43*458a6a73SNicolas Bonnefon## Using filters 44*458a6a73SNicolas Bonnefon 45*458a6a73SNicolas Bonnefon_Filters_ can colorize some lines of the log being displayed, for example to 46*458a6a73SNicolas Bonnefondraw attention to lines indicating an error, or to associate a color with each 47*458a6a73SNicolas Bonnefonsort of event. Any number of filter can be defined in the 'Filters' 48*458a6a73SNicolas Bonnefonconfiguration dialog, each using a regexp against which lines will be matched. 49*458a6a73SNicolas BonnefonFor each line, all filters are tried in order and the fore and back colors of 50*458a6a73SNicolas Bonnefonthe first successful filter are applied. 51*458a6a73SNicolas Bonnefon 52*458a6a73SNicolas Bonnefon## Browsing changing log files 53*458a6a73SNicolas Bonnefon 54*458a6a73SNicolas Bonnefon_glogg_ can display and search through logs while they are written to disk, as 55*458a6a73SNicolas Bonnefonit might be the case when debugging a running program or server. 56*458a6a73SNicolas BonnefonThe log is automatically updated when it grows, but the search must be 57*458a6a73SNicolas Bonnefonmanually restarted for the new matches to be found. 58*458a6a73SNicolas Bonnefon 59*458a6a73SNicolas Bonnefon## Settings 60*458a6a73SNicolas Bonnefon### Font 61*458a6a73SNicolas Bonnefon 62*458a6a73SNicolas BonnefonThe font used to display the log file. A clear, monospace font (like the free, 63*458a6a73SNicolas Bonnefonopen source, [DejaVu Mono](http://www.dejavu-fonts.org/) for example) is 64*458a6a73SNicolas Bonnefonrecommended. 65*458a6a73SNicolas Bonnefon 66*458a6a73SNicolas Bonnefon 67