1/* 2 * $Id: 3da9a5fc88c904673b3b95d0c9667b2bcbccfc80 $ 3 * Time-stamp: "2007-11-16 22:49:11 bkorb" 4 * 5 * This file contains the routines that deal with processing quoted strings 6 * into an internal format. 7 * 8 * This file is part of AutoOpts, a companion to AutoGen. 9 * AutoOpts is free software. 10 * AutoOpts is copyright (c) 1992-2009 by Bruce Korb - all rights reserved 11 * 12 * AutoOpts is available under any one of two licenses. The license 13 * in use must be one of these two and the choice is under the control 14 * of the user of the license. 15 * 16 * The GNU Lesser General Public License, version 3 or later 17 * See the files "COPYING.lgplv3" and "COPYING.gplv3" 18 * 19 * The Modified Berkeley Software Distribution License 20 * See the file "COPYING.mbsd" 21 * 22 * These files have the following md5sums: 23 * 24 * 43b91e8ca915626ed3818ffb1b71248b pkg/libopts/COPYING.gplv3 25 * 06a1a2e4760c90ea5e1dad8dfaac4d39 pkg/libopts/COPYING.lgplv3 26 * 66a5cedaf62c4b2637025f049f9b826f pkg/libopts/COPYING.mbsd 27 */ 28 29/* = = = START-STATIC-FORWARD = = = */ 30/* static forward declarations maintained by mk-fwd */ 31/* = = = END-STATIC-FORWARD = = = */ 32 33/*=export_func ao_string_cook_escape_char 34 * private: 35 * 36 * what: escape-process a string fragment 37 * arg: + char const* + pzScan + points to character after the escape + 38 * arg: + char* + pRes + Where to put the result byte + 39 * arg: + unsigned int + nl_ch + replacement char if scanned char is \n + 40 * 41 * ret-type: unsigned int 42 * ret-desc: The number of bytes consumed processing the escaped character. 43 * 44 * doc: 45 * 46 * This function converts "t" into "\t" and all your other favorite 47 * escapes, including numeric ones: hex and ocatal, too. 48 * The returned result tells the caller how far to advance the 49 * scan pointer (passed in). The default is to just pass through the 50 * escaped character and advance the scan by one. 51 * 52 * Some applications need to keep an escaped newline, others need to 53 * suppress it. This is accomplished by supplying a '\n' replacement 54 * character that is different from \n, if need be. For example, use 55 * 0x7F and never emit a 0x7F. 56 * 57 * err: @code{NULL} is returned if the string is mal-formed. 58=*/ 59unsigned int 60ao_string_cook_escape_char( char const* pzIn, char* pRes, u_int nl ) 61{ 62 unsigned int res = 1; 63 64 switch (*pRes = *pzIn++) { 65 case NUL: /* NUL - end of input string */ 66 return 0; 67 case '\r': 68 if (*pzIn != '\n') 69 return 1; 70 res++; 71 /* FALLTHROUGH */ 72 case '\n': /* NL - emit newline */ 73 *pRes = (char)nl; 74 return res; 75 76 case 'a': *pRes = '\a'; break; 77 case 'b': *pRes = '\b'; break; 78 case 'f': *pRes = '\f'; break; 79 case 'n': *pRes = '\n'; break; 80 case 'r': *pRes = '\r'; break; 81 case 't': *pRes = '\t'; break; 82 case 'v': *pRes = '\v'; break; 83 84 case 'x': 85 case 'X': /* HEX Escape */ 86 if (IS_HEX_DIGIT_CHAR(*pzIn)) { 87 char z[4], *pz = z; 88 89 do *(pz++) = *(pzIn++); 90 while (IS_HEX_DIGIT_CHAR(*pzIn) && (pz < z + 2)); 91 *pz = NUL; 92 *pRes = (unsigned char)strtoul(z, NULL, 16); 93 res += pz - z; 94 } 95 break; 96 97 case '0': case '1': case '2': case '3': 98 case '4': case '5': case '6': case '7': 99 { 100 /* 101 * IF the character copied was an octal digit, 102 * THEN set the output character to an octal value 103 */ 104 char z[4], *pz = z + 1; 105 unsigned long val; 106 z[0] = *pRes; 107 108 while (IS_OCT_DIGIT_CHAR(*pzIn) && (pz < z + 3)) 109 *(pz++) = *(pzIn++); 110 *pz = NUL; 111 val = strtoul(z, NULL, 8); 112 if (val > 0xFF) 113 val = 0xFF; 114 *pRes = (unsigned char)val; 115 res = pz - z; 116 break; 117 } 118 119 default: ; 120 } 121 122 return res; 123} 124 125 126/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 127 * 128 * A quoted string has been found. 129 * Find the end of it and compress any escape sequences. 130 */ 131/*=export_func ao_string_cook 132 * private: 133 * 134 * what: concatenate and escape-process strings 135 * arg: + char* + pzScan + The *MODIFIABLE* input buffer + 136 * arg: + int* + pLineCt + The (possibly NULL) pointer to a line count + 137 * 138 * ret-type: char* 139 * ret-desc: The address of the text following the processed strings. 140 * The return value is NULL if the strings are ill-formed. 141 * 142 * doc: 143 * 144 * A series of one or more quoted strings are concatenated together. 145 * If they are quoted with double quotes (@code{"}), then backslash 146 * escapes are processed per the C programming language. If they are 147 * single quote strings, then the backslashes are honored only when they 148 * precede another backslash or a single quote character. 149 * 150 * err: @code{NULL} is returned if the string(s) is/are mal-formed. 151=*/ 152char* 153ao_string_cook( char* pzScan, int* pLineCt ) 154{ 155 int l = 0; 156 char q = *pzScan; 157 158 /* 159 * It is a quoted string. Process the escape sequence characters 160 * (in the set "abfnrtv") and make sure we find a closing quote. 161 */ 162 char* pzD = pzScan++; 163 char* pzS = pzScan; 164 165 if (pLineCt == NULL) 166 pLineCt = &l; 167 168 for (;;) { 169 /* 170 * IF the next character is the quote character, THEN we may end the 171 * string. We end it unless the next non-blank character *after* the 172 * string happens to also be a quote. If it is, then we will change 173 * our quote character to the new quote character and continue 174 * condensing text. 175 */ 176 while (*pzS == q) { 177 *pzD = NUL; /* This is probably the end of the line */ 178 pzS++; 179 180 scan_for_quote: 181 while (IS_WHITESPACE_CHAR(*pzS)) 182 if (*(pzS++) == '\n') 183 (*pLineCt)++; 184 185 /* 186 * IF the next character is a quote character, 187 * THEN we will concatenate the strings. 188 */ 189 switch (*pzS) { 190 case '"': 191 case '\'': 192 break; 193 194 case '/': 195 /* 196 * Allow for a comment embedded in the concatenated string. 197 */ 198 switch (pzS[1]) { 199 default: return NULL; 200 case '/': 201 /* 202 * Skip to end of line 203 */ 204 pzS = strchr( pzS, '\n' ); 205 if (pzS == NULL) 206 return NULL; 207 (*pLineCt)++; 208 break; 209 210 case '*': 211 { 212 char* p = strstr( pzS+2, "*/" ); 213 /* 214 * Skip to terminating star slash 215 */ 216 if (p == NULL) 217 return NULL; 218 while (pzS < p) { 219 if (*(pzS++) == '\n') 220 (*pLineCt)++; 221 } 222 223 pzS = p + 2; 224 } 225 } 226 goto scan_for_quote; 227 228 default: 229 /* 230 * The next non-whitespace character is not a quote. 231 * The series of quoted strings has come to an end. 232 */ 233 return pzS; 234 } 235 236 q = *(pzS++); /* assign new quote character and advance scan */ 237 } 238 239 /* 240 * We are inside a quoted string. Copy text. 241 */ 242 switch (*(pzD++) = *(pzS++)) { 243 case NUL: 244 return NULL; 245 246 case '\n': 247 (*pLineCt)++; 248 break; 249 250 case '\\': 251 /* 252 * IF we are escaping a new line, 253 * THEN drop both the escape and the newline from 254 * the result string. 255 */ 256 if (*pzS == '\n') { 257 pzS++; 258 pzD--; 259 (*pLineCt)++; 260 } 261 262 /* 263 * ELSE IF the quote character is '"' or '`', 264 * THEN we do the full escape character processing 265 */ 266 else if (q != '\'') { 267 int ct = ao_string_cook_escape_char( pzS, pzD-1, (u_int)'\n' ); 268 if (ct == 0) 269 return NULL; 270 271 pzS += ct; 272 } /* if (q != '\'') */ 273 274 /* 275 * OTHERWISE, we only process "\\", "\'" and "\#" sequences. 276 * The latter only to easily hide preprocessing directives. 277 */ 278 else switch (*pzS) { 279 case '\\': 280 case '\'': 281 case '#': 282 pzD[-1] = *pzS++; 283 } 284 } /* switch (*(pzD++) = *(pzS++)) */ 285 } /* for (;;) */ 286} 287/* 288 * Local Variables: 289 * mode: C 290 * c-file-style: "stroustrup" 291 * indent-tabs-mode: nil 292 * End: 293 * end of autoopts/cook.c */ 294