2018/20180707_cgi_web_tools_aux_exe/arith_large_cgi.c

//$Header$
//********************************************************************************
//This source file is the main function of a program to support number theory
//web pages.
//********************************************************************************
//Copyright (C) 2003 David T. Ashley
//********************************************************************************
//This program 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 of the License, or
//(at your option) any later version.
//
//This program or source file 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 may have received a copy of the GNU General Public License
//along with this program; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//********************************************************************************
//This program is written exclusively to support a PHP script which must calculate and
//display a number of number theory results.  The necessity of this script
//(rather than using BCMATH) comes about because SourceForge does not have
//bcmath installed on its PHP system.
//
//This program is meant to be called by the PHP script using the exec()
//call, but could also be run by hand (and in fact this method is used for testing).
//
//The first parameter after the program name is the suboperation to be performed
//(each CGI page probably uses a different suboperation).  This program
//will return a non-zero exit code only if there is a missing or unrecognized
//suboperation.  Otherwise, error reporting is controlled by the rules of the
//suboperation.
//
//The currently defined suboperations are:
//
//   a)"help"
//     Display information about what the program is and how to use
//     it.
//   b)"gcd"
//     Calculate the gcd of two integers using Euclid's classic
//     algorithm and also display the intermediate results.
//   c)"gmp_prob_prime"
//     Use Miller-Rabin to determine to high certainty whther a 
//     number is prime or composite.
//   d)"pfact_18"     
//     Attempt to factor a number of 18 decimal digits or less into     
//     component primes.
//   e)"cfbrap"
//     Finds the best rational approximation to a rational number subject
//     to constraints on the denominator and numerator using continued
//     fraction techniques.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "auxfuncs.h"
#include "subfunc_cfbrap.h"
#include "subfunc_gcd.h"
#include "subfunc_gmp_prob_prime.h"
#include "subfunc_pfact_18.h"

//Single function prototype needed for a forward reference.
static void dump_subfunction_choices(int indent);

//Implements the help.
int SUBFUNC_HELP_main(int argc, char *argv[])
   {
     int i;
   char *help[] =
     {
     "This program is a compiled 'C'-language program designed to be called from a",
     "PHP script to assist in calculating number theory and large integer",
     "arithmetic results.  This scheme (of having a separate executable like this",
     "one) was used with SourceForge web content because SourceForge did not have",
     "the bcmath library compiled into PHP, and it was determined experimentally",
     "that writing large integer arithmetic functions in PHP directly resulted in",
     "unusably slow performance.  This program makes use of the GMP library, which",
     "gives it superior performance.",
     "",
     "This program can of course be invoked from a shell or from another scripting",
     "language besides PHP.  It is designed, however, for execution from a",
     "scripting language, as you might guess from the human-unfriendly output.",
     "",
     "Please contact Dave Ashley (dtashley@aol.com) with any questions or",
     "concerns.",
     "",
     "Dave Ashley, Detroit, Michigan, USA, April, 2003.",
     "",
     "The available subfunction choices (the first parameter on the command",
     "line) are:",
     };

   for (i=0; i<sizeof(help)/sizeof(help[0]); i++)
     printf("%s\n", help[i]);
   dump_subfunction_choices(3);
   }

//Structure type used to hold the jump table of different functions
//to handle different subcommands.
struct struct_ARITH_LARGE_CGI_subcmd_jmp 
      {
      char *subfunc_string;
      int (*subfunc_ptr)(int argc, char *argv[]);
      };

//The jump table.  The last element is defined to have both a
//NULL string pointer and a NULL function pointer.
static struct struct_ARITH_LARGE_CGI_subcmd_jmp subcmd_jump_tbl[] =
      {
      {"cfbrap",            SUBFUNC_CFBRAP_main               },
      {"gcd",               SUBFUNC_GCD_main                  },
      {"gmp_prob_prime",    SUBFUNC_GMP_PROB_PRIME_main       },
      {"pfact_18",          SUBFUNC_PFACT_18_main             },
      {"help",              SUBFUNC_HELP_main                 },
      {NULL,                NULL                              }
      };

//Dumps the available choices for the subfunction code to the
//standard output, each indented by "indent" characters.
static void dump_subfunction_choices(int indent)
   {
   int i, j;

   for (i=0; subcmd_jump_tbl[i].subfunc_string != NULL; i++)
      {
      for (j=0; j<indent; j++)
         printf(" ");
      printf("%s\n", subcmd_jump_tbl[i].subfunc_string);
      }
   }


int main(int argc, char *argv[])
   {   
   int i;
   int rv;

   if (argc < 2)
      {
      printf("Missing subfunction code.  Choices are:\n");
      dump_subfunction_choices(3);
      exit(4);
      }

   for (i=0; subcmd_jump_tbl[i].subfunc_string != NULL; i++)
      {
      if (!strcmp(argv[1], subcmd_jump_tbl[i].subfunc_string))
         {
         rv = (subcmd_jump_tbl[i].subfunc_ptr)(argc, argv);
         goto normal_return;
         }
      }

   printf("Invalid subfunction code.  Choices are:\n");
   dump_subfunction_choices(3);
   exit(4);

   normal_return:
      exit(rv);
   }

//********************************************************************************
//$Log: arith_large_cgi.c,v $
//Revision 1.6  2003/07/01 03:46:58  dtashley
//Edits towards working continued fraction best rational approximation
//functionality.
//
//Revision 1.5  2003/06/29 22:51:49  dtashley
//Edits toward CF best approximation functionality.
//
//Revision 1.4  2003/04/17 20:02:05  dtashley
//License text for the GPL added.  All source files are now under the GPL,
//after some discussion on the GMP list.
//
//Revision 1.3  2003/04/15 23:55:43  dtashley
//SUBFUNC_PFACT_18 added.
//
//Revision 1.2  2003/04/14 23:27:01  dtashley
//Subfunction GMP_PROB_PRIME finished.
//
//Revision 1.1  2003/04/14 20:38:40  dtashley
//Initial checkin.
//********************************************************************************
//End of file ARITH_LARGE_CGI.C.
//********************************************************************************
1	//$Header$
2	//********************************************************************************
3	//This source file is the main function of a program to support number theory
4	//web pages.
5	//********************************************************************************
6	//Copyright (C) 2003 David T. Ashley
7	//********************************************************************************
8	//This program is free software; you can redistribute it and/or modify
9	//it under the terms of the GNU General Public License as published by
10	//the Free Software Foundation; either version 2 of the License, or
11	//(at your option) any later version.
12	//
13	//This program or source file is distributed in the hope that it will
14	//be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
15	//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16	//GNU General Public License for more details.
17	//
18	//You may have received a copy of the GNU General Public License
19	//along with this program; if not, write to the Free Software
20	//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21	//********************************************************************************
22	//This program is written exclusively to support a PHP script which must calculate and
23	//display a number of number theory results. The necessity of this script
24	//(rather than using BCMATH) comes about because SourceForge does not have
25	//bcmath installed on its PHP system.
26	//
27	//This program is meant to be called by the PHP script using the exec()
28	//call, but could also be run by hand (and in fact this method is used for testing).
29	//
30	//The first parameter after the program name is the suboperation to be performed
31	//(each CGI page probably uses a different suboperation). This program
32	//will return a non-zero exit code only if there is a missing or unrecognized
33	//suboperation. Otherwise, error reporting is controlled by the rules of the
34	//suboperation.
35	//
36	//The currently defined suboperations are:
37	//
38	// a)"help"
39	// Display information about what the program is and how to use
40	// it.
41	// b)"gcd"
42	// Calculate the gcd of two integers using Euclid's classic
43	// algorithm and also display the intermediate results.
44	// c)"gmp_prob_prime"
45	// Use Miller-Rabin to determine to high certainty whther a
46	// number is prime or composite.
47	// d)"pfact_18"
48	// Attempt to factor a number of 18 decimal digits or less into
49	// component primes.
50	// e)"cfbrap"
51	// Finds the best rational approximation to a rational number subject
52	// to constraints on the denominator and numerator using continued
53	// fraction techniques.
54
55	#include <stdio.h>
56	#include <stdlib.h>
57	#include <string.h>
58
59	#include "auxfuncs.h"
60	#include "subfunc_cfbrap.h"
61	#include "subfunc_gcd.h"
62	#include "subfunc_gmp_prob_prime.h"
63	#include "subfunc_pfact_18.h"
64
65	//Single function prototype needed for a forward reference.
66	static void dump_subfunction_choices(int indent);
67
68	//Implements the help.
69	int SUBFUNC_HELP_main(int argc, char *argv[])
70	{
71	int i;
72	char *help[] =
73	{
74	"This program is a compiled 'C'-language program designed to be called from a",
75	"PHP script to assist in calculating number theory and large integer",
76	"arithmetic results. This scheme (of having a separate executable like this",
77	"one) was used with SourceForge web content because SourceForge did not have",
78	"the bcmath library compiled into PHP, and it was determined experimentally",
79	"that writing large integer arithmetic functions in PHP directly resulted in",
80	"unusably slow performance. This program makes use of the GMP library, which",
81	"gives it superior performance.",
82	"",
83	"This program can of course be invoked from a shell or from another scripting",
84	"language besides PHP. It is designed, however, for execution from a",
85	"scripting language, as you might guess from the human-unfriendly output.",
86	"",
87	"Please contact Dave Ashley (dtashley@aol.com) with any questions or",
88	"concerns.",
89	"",
90	"Dave Ashley, Detroit, Michigan, USA, April, 2003.",
91	"",
92	"The available subfunction choices (the first parameter on the command",
93	"line) are:",
94	};
95
96	for (i=0; i<sizeof(help)/sizeof(help[0]); i++)
97	printf("%s\n", help[i]);
98	dump_subfunction_choices(3);
99	}
100
101	//Structure type used to hold the jump table of different functions
102	//to handle different subcommands.
103	struct struct_ARITH_LARGE_CGI_subcmd_jmp
104	{
105	char *subfunc_string;
106	int (subfunc_ptr)(int argc, char argv[]);
107	};
108
109	//The jump table. The last element is defined to have both a
110	//NULL string pointer and a NULL function pointer.
111	static struct struct_ARITH_LARGE_CGI_subcmd_jmp subcmd_jump_tbl[] =
112	{
113	{"cfbrap", SUBFUNC_CFBRAP_main },
114	{"gcd", SUBFUNC_GCD_main },
115	{"gmp_prob_prime", SUBFUNC_GMP_PROB_PRIME_main },
116	{"pfact_18", SUBFUNC_PFACT_18_main },
117	{"help", SUBFUNC_HELP_main },
118	{NULL, NULL }
119	};
120
121	//Dumps the available choices for the subfunction code to the
122	//standard output, each indented by "indent" characters.
123	static void dump_subfunction_choices(int indent)
124	{
125	int i, j;
126
127	for (i=0; subcmd_jump_tbl[i].subfunc_string != NULL; i++)
128	{
129	for (j=0; j<indent; j++)
130	printf(" ");
131	printf("%s\n", subcmd_jump_tbl[i].subfunc_string);
132	}
133	}
134
135
136	int main(int argc, char *argv[])
137	{
138	int i;
139	int rv;
140
141	if (argc < 2)
142	{
143	printf("Missing subfunction code. Choices are:\n");
144	dump_subfunction_choices(3);
145	exit(4);
146	}
147
148	for (i=0; subcmd_jump_tbl[i].subfunc_string != NULL; i++)
149	{
150	if (!strcmp(argv[1], subcmd_jump_tbl[i].subfunc_string))
151	{
152	rv = (subcmd_jump_tbl[i].subfunc_ptr)(argc, argv);
153	goto normal_return;
154	}
155	}
156
157	printf("Invalid subfunction code. Choices are:\n");
158	dump_subfunction_choices(3);
159	exit(4);
160
161	normal_return:
162	exit(rv);
163	}
164
165	//********************************************************************************
166	//$Log: arith_large_cgi.c,v $
167	//Revision 1.6 2003/07/01 03:46:58 dtashley
168	//Edits towards working continued fraction best rational approximation
169	//functionality.
170	//
171	//Revision 1.5 2003/06/29 22:51:49 dtashley
172	//Edits toward CF best approximation functionality.
173	//
174	//Revision 1.4 2003/04/17 20:02:05 dtashley
175	//License text for the GPL added. All source files are now under the GPL,
176	//after some discussion on the GMP list.
177	//
178	//Revision 1.3 2003/04/15 23:55:43 dtashley
179	//SUBFUNC_PFACT_18 added.
180	//
181	//Revision 1.2 2003/04/14 23:27:01 dtashley
182	//Subfunction GMP_PROB_PRIME finished.
183	//
184	//Revision 1.1 2003/04/14 20:38:40 dtashley
185	//Initial checkin.
186	//********************************************************************************
187	//End of file ARITH_LARGE_CGI.C.
188	//********************************************************************************