| 1 | /* Environment-hacking for GNU Emacs subprocess |
| 2 | Copyright (C) 1986 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU Emacs. |
| 5 | |
| 6 | GNU Emacs is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 1, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GNU Emacs is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU Emacs; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | |
| 21 | #include "config.h" |
| 22 | #include "lisp.h" |
| 23 | |
| 24 | #ifdef MAINTAIN_ENVIRONMENT |
| 25 | |
| 26 | #ifdef VMS |
| 27 | you lose -- this is un*x-only |
| 28 | #endif |
| 29 | |
| 30 | /* alist of (name-string . value-string) */ |
| 31 | Lisp_Object Venvironment_alist; |
| 32 | extern char **environ; |
| 33 | |
| 34 | void |
| 35 | set_environment_alist (str, val) |
| 36 | register Lisp_Object str, val; |
| 37 | { |
| 38 | register Lisp_Object tem; |
| 39 | |
| 40 | tem = Fassoc (str, Venvironment_alist); |
| 41 | if (NULL (tem)) |
| 42 | if (NULL (val)) |
| 43 | ; |
| 44 | else |
| 45 | Venvironment_alist = Fcons (Fcons (str, val), Venvironment_alist); |
| 46 | else |
| 47 | if (NULL (val)) |
| 48 | Venvironment_alist = Fdelq (tem, Venvironment_alist); |
| 49 | else |
| 50 | XCONS (tem)->cdr = val; |
| 51 | } |
| 52 | |
| 53 | |
| 54 | |
| 55 | static void |
| 56 | initialize_environment_alist () |
| 57 | { |
| 58 | register unsigned char **e, *s; |
| 59 | extern char *index (); |
| 60 | |
| 61 | for (e = (unsigned char **) environ; *e; e++) |
| 62 | { |
| 63 | s = (unsigned char *) index (*e, '='); |
| 64 | if (s) |
| 65 | set_environment_alist (make_string (*e, s - *e), |
| 66 | build_string (s + 1)); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | \f |
| 71 | unsigned char * |
| 72 | getenv_1 (str, ephemeral) |
| 73 | register unsigned char *str; |
| 74 | int ephemeral; /* if ephmeral, don't need to gc-proof */ |
| 75 | { |
| 76 | register Lisp_Object env; |
| 77 | int len = strlen (str); |
| 78 | |
| 79 | for (env = Venvironment_alist; CONSP (env); env = XCONS (env)->cdr) |
| 80 | { |
| 81 | register Lisp_Object car = XCONS (env)->car; |
| 82 | register Lisp_Object tem = XCONS (car)->car; |
| 83 | |
| 84 | if ((len == XSTRING (tem)->size) && |
| 85 | (!bcmp (str, XSTRING (tem)->data, len))) |
| 86 | { |
| 87 | /* Found it in the lisp environment */ |
| 88 | tem = XCONS (car)->cdr; |
| 89 | if (ephemeral) |
| 90 | /* Caller promises that gc won't make him lose */ |
| 91 | return XSTRING (tem)->data; |
| 92 | else |
| 93 | { |
| 94 | register unsigned char **e; |
| 95 | unsigned char *s; |
| 96 | int ll = XSTRING (tem)->size; |
| 97 | |
| 98 | /* Look for element in the original unix environment */ |
| 99 | for (e = (unsigned char **) environ; *e; e++) |
| 100 | if (!bcmp (str, *e, len) && *(*e + len) == '=') |
| 101 | { |
| 102 | s = *e + len + 1; |
| 103 | if (strlen (s) >= ll) |
| 104 | /* User hasn't either hasn't munged it or has set it |
| 105 | to something shorter -- we don't have to cons */ |
| 106 | goto copy; |
| 107 | else |
| 108 | goto cons; |
| 109 | }; |
| 110 | cons: |
| 111 | /* User has setenv'ed it to a diferent value, and our caller |
| 112 | isn't guaranteeing that he won't stash it away somewhere. |
| 113 | We can't just return a pointer to the lisp string, as that |
| 114 | will be corrupted when gc happens. So, we cons (in such |
| 115 | a way that it can't be freed -- though this isn't such a |
| 116 | problem since the only callers of getenv (as opposed to |
| 117 | those of egetenv) are very early, before the user -could- |
| 118 | have frobbed the environment. */ |
| 119 | s = (unsigned char *) xmalloc (ll + 1); |
| 120 | copy: |
| 121 | bcopy (XSTRING (tem)->data, s, ll + 1); |
| 122 | return (s); |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | return ((unsigned char *) 0); |
| 127 | } |
| 128 | |
| 129 | /* unsigned -- stupid delcaration in lisp.h */ char * |
| 130 | getenv (str) |
| 131 | register unsigned char *str; |
| 132 | { |
| 133 | return ((char *) getenv_1 (str, 0)); |
| 134 | } |
| 135 | |
| 136 | unsigned char * |
| 137 | egetenv (str) |
| 138 | register unsigned char *str; |
| 139 | { |
| 140 | return (getenv_1 (str, 1)); |
| 141 | } |
| 142 | \f |
| 143 | |
| 144 | #if (1 == 1) /* use caller-alloca versions, rather than callee-malloc */ |
| 145 | int |
| 146 | size_of_current_environ () |
| 147 | { |
| 148 | register int size; |
| 149 | Lisp_Object tem; |
| 150 | |
| 151 | tem = Flength (Venvironment_alist); |
| 152 | |
| 153 | size = (XINT (tem) + 1) * sizeof (unsigned char *); |
| 154 | /* + 1 for environment-terminating 0 */ |
| 155 | |
| 156 | for (tem = Venvironment_alist; !NULL (tem); tem = XCONS (tem)->cdr) |
| 157 | { |
| 158 | register Lisp_Object str, val; |
| 159 | |
| 160 | str = XCONS (XCONS (tem)->car)->car; |
| 161 | val = XCONS (XCONS (tem)->car)->cdr; |
| 162 | |
| 163 | size += (XSTRING (str)->size + |
| 164 | XSTRING (val)->size + |
| 165 | 2); /* 1 for '=', 1 for '\000' */ |
| 166 | } |
| 167 | return size; |
| 168 | } |
| 169 | |
| 170 | void |
| 171 | get_current_environ (memory_block) |
| 172 | unsigned char **memory_block; |
| 173 | { |
| 174 | register unsigned char **e, *s; |
| 175 | register int len; |
| 176 | register Lisp_Object tem; |
| 177 | |
| 178 | e = memory_block; |
| 179 | |
| 180 | tem = Flength (Venvironment_alist); |
| 181 | |
| 182 | s = (unsigned char *) memory_block |
| 183 | + (XINT (tem) + 1) * sizeof (unsigned char *); |
| 184 | |
| 185 | for (tem = Venvironment_alist; !NULL (tem); tem = XCONS (tem)->cdr) |
| 186 | { |
| 187 | register Lisp_Object str, val; |
| 188 | |
| 189 | str = XCONS (XCONS (tem)->car)->car; |
| 190 | val = XCONS (XCONS (tem)->car)->cdr; |
| 191 | |
| 192 | *e++ = s; |
| 193 | len = XSTRING (str)->size; |
| 194 | bcopy (XSTRING (str)->data, s, len); |
| 195 | s += len; |
| 196 | *s++ = '='; |
| 197 | len = XSTRING (val)->size; |
| 198 | bcopy (XSTRING (val)->data, s, len); |
| 199 | s += len; |
| 200 | *s++ = '\000'; |
| 201 | } |
| 202 | *e = 0; |
| 203 | } |
| 204 | |
| 205 | #else |
| 206 | /* dead code (this function mallocs, caller frees) superseded by above (which allows caller to use alloca) */ |
| 207 | unsigned char ** |
| 208 | current_environ () |
| 209 | { |
| 210 | unsigned char **env; |
| 211 | register unsigned char **e, *s; |
| 212 | register int len, env_len; |
| 213 | Lisp_Object tem; |
| 214 | Lisp_Object str, val; |
| 215 | |
| 216 | tem = Flength (Venvironment_alist); |
| 217 | |
| 218 | env_len = (XINT (tem) + 1) * sizeof (char *); |
| 219 | /* + 1 for terminating 0 */ |
| 220 | |
| 221 | len = 0; |
| 222 | for (tem = Venvironment_alist; !NULL (tem); tem = XCONS (tem)->cdr) |
| 223 | { |
| 224 | str = XCONS (XCONS (tem)->car)->car; |
| 225 | val = XCONS (XCONS (tem)->car)->cdr; |
| 226 | |
| 227 | len += (XSTRING (str)->size + |
| 228 | XSTRING (val)->size + |
| 229 | 2); |
| 230 | } |
| 231 | |
| 232 | e = env = (unsigned char **) xmalloc (env_len + len); |
| 233 | s = (unsigned char *) env + env_len; |
| 234 | |
| 235 | for (tem = Venvironment_alist; !NULL (tem); tem = XCONS (tem)->cdr) |
| 236 | { |
| 237 | str = XCONS (XCONS (tem)->car)->car; |
| 238 | val = XCONS (XCONS (tem)->car)->cdr; |
| 239 | |
| 240 | *e++ = s; |
| 241 | len = XSTRING (str)->size; |
| 242 | bcopy (XSTRING (str)->data, s, len); |
| 243 | s += len; |
| 244 | *s++ = '='; |
| 245 | len = XSTRING (val)->size; |
| 246 | bcopy (XSTRING (val)->data, s, len); |
| 247 | s += len; |
| 248 | *s++ = '\000'; |
| 249 | } |
| 250 | *e = 0; |
| 251 | |
| 252 | return env; |
| 253 | } |
| 254 | |
| 255 | #endif /* dead code */ |
| 256 | |
| 257 | \f |
| 258 | DEFUN ("getenv", Fgetenv, Sgetenv, 1, 2, "sEnvironment variable: \np", |
| 259 | "Return the value of environment variable VAR, as a string.\n\ |
| 260 | When invoked interactively, print the value in the echo area.\n\ |
| 261 | VAR is a string, the name of the variable,\n\ |
| 262 | or the symbol t, meaning to return an alist representing the\n\ |
| 263 | current environment.") |
| 264 | (str, interactivep) |
| 265 | Lisp_Object str, interactivep; |
| 266 | { |
| 267 | Lisp_Object val; |
| 268 | |
| 269 | if (str == Qt) /* If arg is t, return whole environment */ |
| 270 | return (Fcopy_alist (Venvironment_alist)); |
| 271 | |
| 272 | CHECK_STRING (str, 0); |
| 273 | val = Fcdr (Fassoc (str, Venvironment_alist)); |
| 274 | if (!NULL (interactivep)) |
| 275 | { |
| 276 | if (NULL (val)) |
| 277 | message ("%s not defined in environment", XSTRING (str)->data); |
| 278 | else |
| 279 | message ("\"%s\"", XSTRING (val)->data); |
| 280 | } |
| 281 | return val; |
| 282 | } |
| 283 | |
| 284 | DEFUN ("setenv", Fsetenv, Ssetenv, 1, 2, |
| 285 | "sEnvironment variable: \nsSet %s to value: ", |
| 286 | "Set the value of environment variable VAR to VALUE.\n\ |
| 287 | Both args must be strings. Returns VALUE.") |
| 288 | (str, val) |
| 289 | Lisp_Object str; |
| 290 | Lisp_Object val; |
| 291 | { |
| 292 | Lisp_Object tem; |
| 293 | |
| 294 | CHECK_STRING (str, 0); |
| 295 | if (!NULL (val)) |
| 296 | CHECK_STRING (val, 0); |
| 297 | |
| 298 | set_environment_alist (str, val); |
| 299 | return val; |
| 300 | } |
| 301 | \f |
| 302 | |
| 303 | syms_of_environ () |
| 304 | { |
| 305 | staticpro (&Venvironment_alist); |
| 306 | defsubr (&Ssetenv); |
| 307 | defsubr (&Sgetenv); |
| 308 | } |
| 309 | |
| 310 | init_environ () |
| 311 | { |
| 312 | Venvironment_alist = Qnil; |
| 313 | initialize_environment_alist (); |
| 314 | } |
| 315 | |
| 316 | #endif /* MAINTAIN_ENVIRONMENT */ |