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deb-mbse/lib/debugparse.c
2001-11-25 22:28:04 +00:00

310 lines
10 KiB
C

/* ========================================================================== **
* debugparse.c
*
* Copyright (C) 1998 by Christopher R. Hertel
*
* Email: crh@ubiqx.mn.org
*
* -------------------------------------------------------------------------- **
* This module is a very simple parser for Samba debug log files.
* -------------------------------------------------------------------------- **
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* -------------------------------------------------------------------------- **
* The important function in this module is dbg_char2token(). The rest is
* basically fluff. (Potentially useful fluff, but still fluff.)
* ========================================================================== **
*/
#include "libs.h"
#include "debugparse.h"
/* -------------------------------------------------------------------------- **
* Constants...
*
* DBG_BSIZE - This internal constant is used only by dbg_test(). It is the
* size of the read buffer. I've tested the function using a
* DBG_BSIZE value of 2.
*/
#define DBG_BSIZE 128
/* -------------------------------------------------------------------------- **
* Functions...
*/
char *dbg_token2string( dbg_Token tok )
/* ------------------------------------------------------------------------ **
* Given a token, return a string describing the token.
*
* Input: tok - One of the set of dbg_Tokens defined in debugparse.h.
*
* Output: A string identifying the token. This is useful for debugging,
* etc.
*
* Note: If the token is not known, this function will return the
* string "<unknown>".
*
* ------------------------------------------------------------------------ **
*/
{
switch( tok )
{
case dbg_null:
return( (char *)"null" );
case dbg_ignore:
return( (char *)"ignore" );
case dbg_header:
return( (char *)"header" );
case dbg_timestamp:
return( (char *)"time stamp" );
case dbg_level:
return( (char *)"level" );
case dbg_sourcefile:
return( (char *)"source file" );
case dbg_function:
return( (char *)"function" );
case dbg_lineno:
return( (char *)"line number" );
case dbg_message:
return( (char *)"message" );
case dbg_eof:
return( (char *)"[EOF]" );
}
return( (char *)"<unknown>" );
} /* dbg_token2string */
dbg_Token dbg_char2token( dbg_Token *state, int c )
/* ------------------------------------------------------------------------ **
* Parse input one character at a time.
*
* Input: state - A pointer to a token variable. This is used to
* maintain the parser state between calls. For
* each input stream, you should set up a separate
* state variable and initialize it to dbg_null.
* Pass a pointer to it into this function with each
* character in the input stream. See dbg_test()
* for an example.
* c - The "current" character in the input stream.
*
* Output: A token.
* The token value will change when delimiters are found,
* which indicate a transition between syntactical objects.
* Possible return values are:
*
* dbg_null - The input character was an end-of-line.
* This resets the parser to its initial state
* in preparation for parsing the next line.
* dbg_eof - Same as dbg_null, except that the character
* was an end-of-file.
* dbg_ignore - Returned for whitespace and delimiters.
* These lexical tokens are only of interest
* to the parser.
* dbg_header - Indicates the start of a header line. The
* input character was '[' and was the first on
* the line.
* dbg_timestamp - Indicates that the input character was part
* of a header timestamp.
* dbg_level - Indicates that the input character was part
* of the debug-level value in the header.
* dbg_sourcefile - Indicates that the input character was part
* of the sourcefile name in the header.
* dbg_function - Indicates that the input character was part
* of the function name in the header.
* dbg_lineno - Indicates that the input character was part
* of the DEBUG call line number in the header.
* dbg_message - Indicates that the input character was part
* of the DEBUG message text.
*
* ------------------------------------------------------------------------ **
*/
{
/* The terminating characters that we see will greatly depend upon
* how they are read. For example, if gets() is used instead of
* fgets(), then we will not see newline characters. A lot also
* depends on the calling function, which may handle terminators
* itself.
*
* '\n', '\0', and EOF are all considered line terminators. The
* dbg_eof token is sent back if an EOF is encountered.
*
* Warning: only allow the '\0' character to be sent if you are
* using gets() to read whole lines (thus replacing '\n'
* with '\0'). Sending '\0' at the wrong time will mess
* up the parsing.
*/
switch( c )
{
case EOF:
*state = dbg_null; /* Set state to null (initial state) so */
return( dbg_eof ); /* that we can restart with new input. */
case '\n':
case '\0':
*state = dbg_null; /* A newline or eoln resets to the null state. */
return( dbg_null );
}
/* When within the body of the message, only a line terminator
* can cause a change of state. We've already checked for line
* terminators, so if the current state is dbg_msgtxt, simply
* return that as our current token.
*/
if( dbg_message == *state )
return( dbg_message );
/* If we are at the start of a new line, and the input character
* is an opening bracket, then the line is a header line, otherwise
* it's a message body line.
*/
if( dbg_null == *state )
{
if( '[' == c )
{
*state = dbg_timestamp;
return( dbg_header );
}
*state = dbg_message;
return( dbg_message );
}
/* We've taken care of terminators, text blocks and new lines.
* The remaining possibilities are all within the header line
* itself.
*/
/* Within the header line, whitespace can be ignored *except*
* within the timestamp.
*/
if( isspace( c ) )
{
/* Fudge. The timestamp may contain space characters. */
if( (' ' == c) && (dbg_timestamp == *state) )
return( dbg_timestamp );
/* Otherwise, ignore whitespace. */
return( dbg_ignore );
}
/* Okay, at this point we know we're somewhere in the header.
* Valid header *states* are: dbg_timestamp, dbg_level,
* dbg_sourcefile, dbg_function, and dbg_lineno.
*/
switch( c )
{
case ',':
if( dbg_timestamp == *state )
{
*state = dbg_level;
return( dbg_ignore );
}
break;
case ']':
if( dbg_level == *state )
{
*state = dbg_sourcefile;
return( dbg_ignore );
}
break;
case ':':
if( dbg_sourcefile == *state )
{
*state = dbg_function;
return( dbg_ignore );
}
break;
case '(':
if( dbg_function == *state )
{
*state = dbg_lineno;
return( dbg_ignore );
}
break;
case ')':
if( dbg_lineno == *state )
{
*state = dbg_null;
return( dbg_ignore );
}
break;
}
/* If the previous block did not result in a state change, then
* return the current state as the current token.
*/
return( *state );
} /* dbg_char2token */
void dbg_test( void )
/* ------------------------------------------------------------------------ **
* Simple test function.
*
* Input: none.
* Output: none.
* Notes: This function was used to test dbg_char2token(). It reads a
* Samba log file from stdin and prints parsing info to stdout.
* It also serves as a simple example.
*
* ------------------------------------------------------------------------ **
*/
{
char bufr[DBG_BSIZE];
int i;
int linecount = 1;
dbg_Token old = dbg_null,
new = dbg_null,
state = dbg_null;
while( fgets( bufr, DBG_BSIZE, stdin ) )
{
for( i = 0; bufr[i]; i++ )
{
old = new;
new = dbg_char2token( &state, bufr[i] );
switch( new )
{
case dbg_header:
if( linecount > 1 )
(void)putchar( '\n' );
break;
case dbg_null:
linecount++;
break;
case dbg_ignore:
break;
default:
if( old != new )
(void)printf( "\n[%05d]%12s: ", linecount, dbg_token2string(new) );
(void)putchar( bufr[i] );
}
}
}
(void)putchar( '\n' );
} /* dbg_test */
/* -------------------------------------------------------------------------- **
* This simple main line can be uncommented and used to test the parser.
*/
/*
* int main( void )
* {
* dbg_test();
* return( 0 );
* }
*/
/* ========================================================================== */