1 /*============================================================================== 2 | 3 | File Name: 4 | 5 | ppIO.c 6 | 7 | Description: 8 | 9 | Command line parsing and polynomial pretty printing. 10 | 11 | Functions: 12 | 13 | parse_command_line 14 | write_poly 15 | 16 | LEGAL 17 | 18 | Primpoly Version 16.1 - A Program for Computing Primitive Polynomials. 19 | Copyright (C) 1999-2021 by Sean Erik O'Connor. All Rights Reserved. 20 | 21 | This program is free software: you can redistribute it and/or modify 22 | it under the terms of the GNU General Public License as published by 23 | the Free Software Foundation, either version 3 of the License, or 24 | (at your option) any later version. 25 | 26 | This program is distributed in the hope that it will be useful, 27 | but WITHOUT ANY WARRANTY; without even the implied warranty of 28 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 29 | GNU General Public License for more details. 30 | 31 | You should have received a copy of the GNU General Public License 32 | along with this program. If not, see <http://www.gnu.org/licenses/>. 33 | 34 | The author's address is artificer!AT!seanerikoconnor!DOT!freeservers!DOT!com 35 | with !DOT! replaced by . and the !AT! replaced by @ 36 | 37 ==============================================================================*/ 38 39 /*------------------------------------------------------------------------------ 40 | Include Files | 41 ------------------------------------------------------------------------------*/ 42 43 #include <stdio.h> /* for printf() */ 44 #include <stdlib.h> /* for _MAX_PATH */ 45 46 #include "Primpoly.h" 47 48 49 /*============================================================================== 50 | parse_command_line | 51 ================================================================================ 52 53 DESCRIPTION 54 55 Parse the command line. 56 57 INPUT 58 n 59 a[] (int *) Coefficients of the nth degree polynomial a(x) = a x + ... 60 n 61 + a x + a. a is stored at array location a[i], 62 1 0 i 63 0 <= i < n . 64 65 n (int) The polynomial's degree. 66 67 OUTPUT 68 69 testPolynomialForPrimitivity 70 71 72 EXAMPLE CALLING SEQUENCE 73 74 pp -h Prints help. 75 pp -s 2 4 Prints search statistics. 76 pp -t 2 4 x^3+x^2+1 Checks a polynomial for primitivity. No blanks, please! 77 pp -a 2 4 Lists all primitive polynomials of degree 4 modulo 2. 78 pp -c 2 4 Does a time-consuming double check on primitivity. 79 80 METHOD 81 82 83 84 BUGS 85 86 None. 87 88 89 -------------------------------------------------------------------------------- 90 | Function Call | 91 ------------------------------------------------------------------------------*/ 92 93 int parse_command_line( int argc, 94 char * argv[], 95 int * testPolynomialForPrimitivity, 96 int * listAllPrimitivePolynomials, 97 int * printStatistics, 98 int * printHelp, 99 int * selfCheck, 100 int * p, 101 int * n, 102 int * testPolynomial ) 103 { 104 105 int input_arg_index ; 106 char * input_arg_string ; 107 char * option_ptr ; 108 109 int num_arg ; 110 char * arg_string[ _MAX_PATH ] ; 111 112 /* Initialize to defaults. */ 113 *testPolynomialForPrimitivity = NO ; 114 *listAllPrimitivePolynomials = NO ; 115 *printStatistics = NO ; 116 *printHelp = NO ; 117 *selfCheck = NO ; 118 *p = 0 ; 119 *n = 0 ; 120 testPolynomial = (int *) 0 ; 121 122 123 /* 124 * Parse the command line to get the options and their inputs. 125 */ 126 127 for (input_arg_index = 0, num_arg = 0 ; input_arg_index < argc ; 128 ++input_arg_index) 129 { 130 /* Get next argument string. */ 131 input_arg_string = argv[ input_arg_index ] ; 132 133 /* We have an option: a hyphen followed by a non-null string. */ 134 if (input_arg_string[ 0 ] == '-' && input_arg_string[ 1 ] != '\0') 135 { 136 /* Scan all options. */ 137 for (option_ptr = input_arg_string + 1 ; *option_ptr != '\0' ; 138 ++option_ptr) 139 { 140 switch( *option_ptr ) 141 { 142 /* Test a given polynomial for primitivity. */ 143 case 't': 144 *testPolynomialForPrimitivity = YES ; 145 break ; 146 147 /* List all primitive polynomials. */ 148 case 'a': 149 *listAllPrimitivePolynomials = YES ; 150 break ; 151 152 /* Print statistics on program operation. */ 153 case 's': 154 *printStatistics = YES ; 155 break ; 156 157 /* Print help. */ 158 case 'h': 159 case 'H': 160 *printHelp = YES ; 161 break ; 162 163 /* Turn on all self-checking (slow!). */ 164 case 'c': 165 *selfCheck = YES ; 166 break ; 167 168 default: 169 printf( "Cannot recognize the option %c\n", *option_ptr ) ; 170 break ; 171 } 172 } 173 } 174 else /* Not an option, but an argument. */ 175 { 176 arg_string[ num_arg++ ] = input_arg_string ; 177 } 178 } 179 180 181 /* Assume the next two arguments are p and n. */ 182 if (num_arg == 3) 183 { 184 *p = atoi( arg_string[ 1 ] ) ; 185 *n = atoi( arg_string[ 2 ] ) ; 186 187 } 188 else 189 { 190 printf( "ERROR: Expecting two arguments, p and n.\n\n" ) ; 191 *printHelp = YES ; 192 } 193 194 return 0 ; 195 196 } /* ================ end of function parse_command_line ==================== */ 197 198 199 /*============================================================================== 200 | write_poly | 201 ================================================================================ 202 203 DESCRIPTION 204 205 Print a polynomial in a nice format. Omit terms with coefficients of zero. 206 Suppress coefficients of 1, but not the constant term. Put every 207 NUMTERMSPERLINE terms in the polynomial on a new line. 208 209 INPUT 210 n 211 a[] (int *) Coefficients of the nth degree polynomial a(x) = a x + ... 212 n 213 + a x + a. a is stored at array location a[i], 214 1 0 i 215 0 <= i < n . 216 217 n (int) The polynomial's degree. 218 219 OUTPUT 220 221 Standard output A pretty-printed polynomial. 222 223 EXAMPLE CALLING SEQUENCE 224 225 If array a[] contains 226 227 a[0] = 1 228 a[1] = 2 229 a[2] = 0 230 a[3] = 1 231 232 and n = 3, 233 234 write_poly( a, n ) prints 235 236 x ^ 3 + 2 x + 1 237 238 METHOD 239 240 Sheer hacking ingenuity (vulgarity?). 241 242 BUGS 243 244 None. 245 246 -------------------------------------------------------------------------------- 247 | Function Call | 248 ------------------------------------------------------------------------------*/ 249 250 void write_poly( int * a, int n ) 251 { 252 253 /*------------------------------------------------------------------------------ 254 | Local Variables | 255 ------------------------------------------------------------------------------*/ 256 257 int 258 k, /* Loop conter. */ 259 coeff, /* Coefficient a sub k. */ 260 first_time_through = YES, /* = NO after printing the first coefficient. */ 261 num_terms = 0 ; /* Number of terms printed so far. */ 262 263 /*------------------------------------------------------------------------------ 264 | Function Body | 265 ------------------------------------------------------------------------------*/ 266 267 for (k = n ; k >= 0 ; --k) 268 { 269 270 /* 271 k 272 Print the term a x if a is nonzero. 273 k k 274 */ 275 276 if ( (coeff = a[ k ]) != 0) 277 { 278 279 /* After the first time thorough, print leading plus signs "+" to 280 separate the terms of the polynomial. */ 281 282 if (!first_time_through) 283 284 printf( " + " ) ; 285 286 first_time_through = NO ; 287 288 /* Always print the constant term a but print terms of higher degree 289 0 290 only if a is not 1. 291 k */ 292 293 if ( (coeff != 1) || (k == 0) ) 294 295 printf( "%d", coeff ) ; 296 297 298 /* k 1 0 299 Print the term x. Exceptions: print x, not x, omit x */ 300 301 if (k > 1) 302 303 printf( " x ^ %d", k ) ; 304 305 else if (k == 1) 306 307 printf( " x" ) ; 308 309 /* Start a new line. */ 310 311 if (++num_terms % NUMTERMSPERLINE == 0) 312 313 printf( "\n" ) ; 314 315 } /* end if coeff > 0 */ 316 317 } /* end for */ 318 319 printf( "\n" ) ; 320 321 return ; 322 323 } /* ======================= end of function write_poly ===================== */
