1119483Sobrien/*- 238716Smsmith * Redistribution and use in source and binary forms, with or without 338716Smsmith * modification, are permitted provided that the following conditions 438716Smsmith * are met: 538716Smsmith * 1. Redistributions of source code must retain the above copyright 638716Smsmith * notice, this list of conditions and the following disclaimer. 738716Smsmith * 2. Redistributions in binary form must reproduce the above copyright 838716Smsmith * notice, this list of conditions and the following disclaimer in the 938716Smsmith * documentation and/or other materials provided with the distribution. 1038716Smsmith * 1138716Smsmith * Jordan K. Hubbard 1238716Smsmith * 29 August 1998 1338716Smsmith * 1438716Smsmith * The meat of the simple parser. 1538716Smsmith */ 1638716Smsmith 17119483Sobrien#include <sys/cdefs.h> 18119483Sobrien__FBSDID("$FreeBSD$"); 19119483Sobrien 2038716Smsmith#include <stand.h> 2138716Smsmith#include <string.h> 2264187Sjhb#include "bootstrap.h" 2338716Smsmith 2464187Sjhbstatic void clean(void); 2564187Sjhbstatic int insert(int *argcp, char *buf); 2664187Sjhbstatic char *variable_lookup(char *name); 2738716Smsmith 2838716Smsmith#define PARSE_BUFSIZE 1024 /* maximum size of one element */ 2938716Smsmith#define MAXARGS 20 /* maximum number of elements */ 3038716Smsmithstatic char *args[MAXARGS]; 3138716Smsmith 3238716Smsmith/* 3338716Smsmith * parse: accept a string of input and "parse" it for backslash 3438716Smsmith * substitutions and environment variable expansions (${var}), 3538716Smsmith * returning an argc/argv style vector of whitespace separated 3638716Smsmith * arguments. Returns 0 on success, 1 on failure (ok, ok, so I 3738716Smsmith * wimped-out on the error codes! :). 3838716Smsmith * 3938716Smsmith * Note that the argv array returned must be freed by the caller, but 4038716Smsmith * we own the space allocated for arguments and will free that on next 4138716Smsmith * invocation. This allows argv consumers to modify the array if 4238716Smsmith * required. 4338716Smsmith * 4438716Smsmith * NB: environment variables that expand to more than one whitespace 4538716Smsmith * separated token will be returned as a single argv[] element, not 4638716Smsmith * split in turn. Expanded text is also immune to further backslash 4738716Smsmith * elimination or expansion since this is a one-pass, non-recursive 4838716Smsmith * parser. You didn't specify more than this so if you want more, ask 4938716Smsmith * me. - jkh 5038716Smsmith */ 5138716Smsmith 5238716Smsmith#define PARSE_FAIL(expr) \ 5338716Smsmithif (expr) { \ 5438716Smsmith printf("fail at line %d\n", __LINE__); \ 5538716Smsmith clean(); \ 5638716Smsmith free(copy); \ 5738716Smsmith free(buf); \ 5838716Smsmith return 1; \ 5938716Smsmith} 6038716Smsmith 6138716Smsmith/* Accept the usual delimiters for a variable, returning counterpart */ 6238716Smsmithstatic char 6364187Sjhbisdelim(int ch) 6438716Smsmith{ 6538716Smsmith if (ch == '{') 6638716Smsmith return '}'; 6738716Smsmith else if (ch == '(') 6838716Smsmith return ')'; 6938716Smsmith return '\0'; 7038716Smsmith} 7138716Smsmith 7238765Sjkhstatic int 7364187Sjhbisquote(int ch) 7438765Sjkh{ 7538765Sjkh return (ch == '\'' || ch == '"'); 7638765Sjkh} 7738765Sjkh 7838716Smsmithint 7938716Smsmithparse(int *argc, char ***argv, char *str) 8038716Smsmith{ 8138716Smsmith int ac; 8238716Smsmith char *val, *p, *q, *copy = NULL; 8364187Sjhb size_t i = 0; 8438765Sjkh char token, tmp, quote, *buf; 8538716Smsmith enum { STR, VAR, WHITE } state; 8638716Smsmith 8738716Smsmith ac = *argc = 0; 8838765Sjkh quote = 0; 8938716Smsmith if (!str || (p = copy = backslash(str)) == NULL) 9038716Smsmith return 1; 9138716Smsmith 9238716Smsmith /* Initialize vector and state */ 9338716Smsmith clean(); 9438716Smsmith state = STR; 9538765Sjkh buf = (char *)malloc(PARSE_BUFSIZE); 9638716Smsmith token = 0; 9738716Smsmith 9838716Smsmith /* And awaaaaaaaaay we go! */ 9938716Smsmith while (*p) { 10038716Smsmith switch (state) { 10138716Smsmith case STR: 10242465Smsmith if ((*p == '\\') && p[1]) { 10342465Smsmith p++; 10442465Smsmith PARSE_FAIL(i == (PARSE_BUFSIZE - 1)); 10542620Smsmith buf[i++] = *p++; 10642465Smsmith } else if (isquote(*p)) { 10738765Sjkh quote = quote ? 0 : *p; 10838765Sjkh ++p; 10938765Sjkh } 11038765Sjkh else if (isspace(*p) && !quote) { 11138716Smsmith state = WHITE; 11238716Smsmith if (i) { 11338716Smsmith buf[i] = '\0'; 11438716Smsmith PARSE_FAIL(insert(&ac, buf)); 11538716Smsmith i = 0; 11638716Smsmith } 11738716Smsmith ++p; 11838716Smsmith } else if (*p == '$') { 11938716Smsmith token = isdelim(*(p + 1)); 12038716Smsmith if (token) 12138716Smsmith p += 2; 12238716Smsmith else 12338716Smsmith ++p; 12438716Smsmith state = VAR; 12538716Smsmith } else { 12638716Smsmith PARSE_FAIL(i == (PARSE_BUFSIZE - 1)); 12738716Smsmith buf[i++] = *p++; 12838716Smsmith } 12938716Smsmith break; 13038716Smsmith 13138716Smsmith case WHITE: 13238716Smsmith if (isspace(*p)) 13338716Smsmith ++p; 13438716Smsmith else 13538716Smsmith state = STR; 13638716Smsmith break; 13738716Smsmith 13838716Smsmith case VAR: 13938716Smsmith if (token) { 14038716Smsmith PARSE_FAIL((q = index(p, token)) == NULL); 14138716Smsmith } else { 14238716Smsmith q = p; 14338716Smsmith while (*q && !isspace(*q)) 14438716Smsmith ++q; 14538716Smsmith } 14638716Smsmith tmp = *q; 14738716Smsmith *q = '\0'; 14838716Smsmith if ((val = variable_lookup(p)) != NULL) { 14964187Sjhb size_t len = strlen(val); 15038716Smsmith 15138716Smsmith strncpy(buf + i, val, PARSE_BUFSIZE - (i + 1)); 15238789Smsmith i += min(len, PARSE_BUFSIZE - 1); 15338716Smsmith } 15438716Smsmith *q = tmp; /* restore value */ 15538716Smsmith p = q + (token ? 1 : 0); 15638716Smsmith state = STR; 15738716Smsmith break; 15838716Smsmith } 15938716Smsmith } 16038716Smsmith /* If at end of token, add it */ 16138716Smsmith if (i && state == STR) { 16238716Smsmith buf[i] = '\0'; 16338716Smsmith PARSE_FAIL(insert(&ac, buf)); 16438716Smsmith } 16538716Smsmith args[ac] = NULL; 16638716Smsmith *argc = ac; 16738765Sjkh *argv = (char **)malloc((sizeof(char *) * ac + 1)); 16838716Smsmith bcopy(args, *argv, sizeof(char *) * ac + 1); 16944570Sdcs free(buf); 17038716Smsmith free(copy); 17138716Smsmith return 0; 17238716Smsmith} 17338716Smsmith 17438716Smsmith#define MAXARGS 20 17538716Smsmith 17638716Smsmith/* Clean vector space */ 17738716Smsmithstatic void 17838716Smsmithclean(void) 17938716Smsmith{ 18038716Smsmith int i; 18138716Smsmith 18238716Smsmith for (i = 0; i < MAXARGS; i++) { 18338716Smsmith if (args[i] != NULL) { 18438716Smsmith free(args[i]); 18538716Smsmith args[i] = NULL; 18638716Smsmith } 18738716Smsmith } 18838716Smsmith} 18938716Smsmith 19038716Smsmithstatic int 19138716Smsmithinsert(int *argcp, char *buf) 19238716Smsmith{ 19338716Smsmith if (*argcp >= MAXARGS) 19438716Smsmith return 1; 19538716Smsmith args[(*argcp)++] = strdup(buf); 19638716Smsmith return 0; 19738716Smsmith} 19838716Smsmith 19938716Smsmithstatic char * 20038716Smsmithvariable_lookup(char *name) 20138716Smsmith{ 20238716Smsmith /* XXX search "special variable" space first? */ 20338716Smsmith return (char *)getenv(name); 20438716Smsmith} 205