/* $Id$ * $URL$ * * plugin template * * Copyright (C) 2003 Michael Reinelt <michael@reinelt.co.at> * Copyright (C) 2004, 2005, 2006, 2007, 2008 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net> * * This file is part of LCD4Linux. * * LCD4Linux is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * LCD4Linux 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ /* * exported functions: * * int plugin_init_sample (void) * adds various functions * */ #include "config.h" /* these should always be included */ #include "debug.h" #include "plugin.h" /* define the include files you need */ #include <stdlib.h> #include <string.h> #include <ctype.h> #ifdef WITH_DMALLOC #include <dmalloc.h> #endif /* sample function 'mul2' */ /* takes one argument, a number */ /* multiplies the number by 2.0 */ /* Note: all local functions should be declared 'static' */ static void my_mul2(RESULT * result, RESULT * arg1) { double param; double value; /* Get Parameter */ /* R2N stands for 'Result to Number' */ param = R2N(arg1); /* calculate value */ value = param * 2.0; /* store result */ /* when called with R_NUMBER, it assumes the */ /* next parameter to be a pointer to double */ SetResult(&result, R_NUMBER, &value); } /* sample function 'mul3' */ /* takes one argument, a number */ /* multiplies the number by 3.0 */ /* same as 'mul2', but shorter */ static void my_mul3(RESULT * result, RESULT * arg1) { /* do it all in one line */ double value = R2N(arg1) * 3.0; /* store result */ SetResult(&result, R_NUMBER, &value); } /* sample function 'diff' */ /* takes two arguments, both numbers */ /* returns |a-b| */ static void my_diff(RESULT * result, RESULT * arg1, RESULT * arg2) { /* do it all in one line */ double value = R2N(arg1) - R2N(arg2); /* some more calculations... */ if (value < 0) value = -value; /* store result */ SetResult(&result, R_NUMBER, &value); } /* sample function 'answer' */ /* takes no argument! */ /* returns the answer to all questions */ static void my_answer(RESULT * result) { /* we have to declare a variable because */ /* SetResult needs a pointer */ double value = 42; /* store result */ SetResult(&result, R_NUMBER, &value); } /* sample function 'length' */ /* takes one argument, a string */ /* returns the string length */ static void my_length(RESULT * result, RESULT * arg1) { /* Note #1: value *must* be double! */ /* Note #2: R2S stands for 'Result to String' */ double value = strlen(R2S(arg1)); /* store result */ SetResult(&result, R_NUMBER, &value); } /* sample function 'upcase' */ /* takes one argument, a string */ /* returns the string in upper case letters */ static void my_upcase(RESULT * result, RESULT * arg1) { char *value, *p; /* create a local copy of the argument */ /* Do *NOT* try to modify the original string! */ value = strdup(R2S(arg1)); /* process the string */ for (p = value; *p != '\0'; p++) *p = toupper(*p); /* store result */ /* when called with R_STRING, it assumes the */ /* next parameter to be a pointer to a string */ /* 'value' is already a char*, so use 'value', not '&value' */ SetResult(&result, R_STRING, value); /* free local copy again */ /* Note that SetResult() makes its own string copy */ free(value); } /* sample function 'cat' */ /* takes variable number of arguments, all strings */ /* returns all prameters concatenated */ static void my_concat(RESULT * result, int argc, RESULT * argv[]) { int i, len; char *value, *part; /* start with a empty string */ value = strdup(""); /* process all arguments */ for (i = 0; i < argc; i++) { part = R2S(argv[i]); len = strlen(value) + strlen(part); value = realloc(value, len + 1); strcat(value, part); } /* store result */ SetResult(&result, R_STRING, value); /* free local string */ free(value); } /* plugin initialization */ /* MUST NOT be declared 'static'! */ int plugin_init_sample(void) { /* register all our cool functions */ /* the second parameter is the number of arguments */ /* -1 stands for variable argument list */ AddFunction("sample::mul2", 1, my_mul2); AddFunction("sample::mul3", 1, my_mul3); AddFunction("sample::answer", 0, my_answer); AddFunction("sample::diff", 2, my_diff); AddFunction("sample::length", 1, my_length); AddFunction("sample::upcase", 1, my_upcase); AddFunction("sample::concat", -1, my_concat); return 0; } void plugin_exit_sample(void) { /* free any allocated memory */ /* close filedescriptors */ }