/* $OpenBSD: interpreter.c,v 1.36 2024/09/20 02:00:46 jsg Exp $ */ /* * This file is in the public domain. * * Author: Mark Lumsden */ /* * This file attempts to add some 'scripting' functionality into mg. * * The initial goal is to give mg the ability to use its existing functions * and structures in a linked-up way. Hopefully resulting in user definable * functions. The syntax is 'scheme' like but currently it is not a scheme * interpreter. * * At the moment there is no manual page reference to this file. The code below * is liable to change, so use at your own risk! * * If you do want to do some testing, you can add some lines to your .mg file * like: * * 1. Give multiple arguments to a function that usually would accept only one: * (find-file "a.txt" "b.txt" "c.txt") * * 2. Define a single value variable: * (define myfile "d.txt") * * 3. Define a list: * (define myfiles(list "e.txt" "f.txt")) * * 4. Use the previously defined variable or list: * (find-file myfiles) * * To do: * 1. multiline parsing - currently only single lines supported. * 2. parsing for '(' and ')' throughout whole string and evaluate correctly. * 3. conditional execution. * 4. have memory allocated dynamically for variable values. * 5. do symbol names need more complex regex patterns? [A-Za-z][.0-9_A-Z+a-z-] * at the moment. * 6. display line numbers with parsing errors. * 7. oh so many things.... * [...] * n. implement user definable functions. * * Notes: * - Currently calls to excline() from this file have the line length and * line number set to zero. * That's because excline() uses '\0' as the end of line indicator * and only the call to foundparen() within excline() uses excline's 2nd * and 3rd arguments. * Importantly, any lines sent to there from here will not be * coming back here. */ #include #include #include #include #include #include #include #include #include "def.h" #include "funmap.h" #ifdef MGLOG #include "kbd.h" #include "log.h" #endif static int multiarg(char *, char *, int); static int isvar(char **, char **, int); /*static int dofunc(char **, char **, int);*/ static int founddef(char *, int, int, int, int); static int foundlst(char *, int, int, int); static int expandvals(char *, char *, char *); static int foundfun(char *, int); static int doregex(char *, char *); static void clearexp(void); static int parse(char *, const char *, const char *, int, int, int, int); static int parsdef(char *, const char *, const char *, int, int, int); static int parsval(char *, const char *, const char *, int, int, int); static int parsexp(char *, const char *, const char *, int, int, int); static int exitinterpreter(char *, char *, int); TAILQ_HEAD(exphead, expentry) ehead; struct expentry { TAILQ_ENTRY(expentry) eentry; char *fun; /* The 1st string found between parens. */ char funbuf[BUFSIZE]; const char *par1; /* Parenthesis at start of string */ const char *par2; /* Parenthesis at end of string */ int expctr; /* An incremental counter:+1 for each exp */ int blkid; /* Which block are we in? */ }; /* * Structure for scheme keywords. */ #define NUMSCHKEYS 4 #define MAXLENSCHKEYS 17 /* 17 = longest keyword (16) + 1 */ char scharkey[NUMSCHKEYS][MAXLENSCHKEYS] = { "define", "list", "if", "lambda" }; static const char lp = '('; static const char rp = ')'; static char *defnam = NULL; static int lnm; /* * Line has a '(' as the first non-white char. * Do some very basic parsing of line. * Multi-line not supported at the moment, To do. */ int foundparen(char *funstr, int llen, int lnum) { const char *lrp = NULL; char *p, *begp = NULL, *endp = NULL, *prechr; char *lastchr = NULL; int i, ret, pctr, expctr, blkid, inquote, esc; int elen, spc, ns; pctr = expctr = inquote = esc = elen = spc = ns = 0; blkid = 1; lnm = lnum; /* * load expressions into a list called 'expentry', to be processd * when all are obtained. * Not really live code at the moment. Just part of the process of * working out what needs to be done. */ TAILQ_INIT(&ehead); /* * Check for blocks of code with opening and closing (). * One block = (cmd p a r a m) * Two blocks = (cmd p a r a m s)(hola) * Two blocks = (cmd p a r (list a m s))(hola) * Only single line at moment, but more for multiline. */ p = funstr; for (i = 0; i < llen; ++i, p++) { if (pctr == 0 && *p != ' ' && *p != '\t' && *p != '(') { if (*p == ')') return(dobeep_num("Extra ')' found on line:", lnm)); return(dobeep_num("Error line:", lnm)); } if (begp != NULL) elen++; if (*p == '\\') { esc = 1; } else if (*p == '(') { if (lastchr != NULL && *lastchr == '(') return(dobeep_num("Multiple consecutive "\ "left parantheses line", lnm)); if (inquote == 0) { if (begp != NULL) { if (*prechr == ' ') ns--; if (endp == NULL) *p = '\0'; else *endp = '\0'; ret = parse(begp, lrp, &lp, blkid, ++expctr, elen - spc, ns); if (!ret) { cleanup(); return(ret); } elen = 0; } lrp = &lp; begp = endp = NULL; pctr++; } else if (inquote != 1) { cleanup(); return(dobeep_num("Opening and closing quote "\ "char error line:", lnm)); } esc = spc = 0; } else if (*p == ')') { if (lastchr != NULL && *lastchr == '(') return(dobeep_num("Empty parenthesis "\ "not supported line", lnm)); if (inquote == 0) { if (begp != NULL) { if (*prechr == ' ') ns--; if (endp == NULL) *p = '\0'; else *endp = '\0'; ret = parse(begp, lrp, &rp, blkid, ++expctr, elen - spc, ns); if (!ret) { cleanup(); return(ret); } elen = 0; } lrp = &rp; begp = endp = NULL; pctr--; } else if (inquote != 1) { cleanup(); return(dobeep_num("Opening and closing quote "\ "char error line:", lnm)); } esc = spc = 0; } else if (*p != ' ' && *p != '\t') { if (begp == NULL) { begp = p; if (*begp == '"' || isdigit(*begp)) return(dobeep_num("First char of "\ "expression error line:", lnm)); } if (*p == '"') { if (inquote == 0 && esc == 0) { if (*prechr != ' ' && *prechr != '\t') return(dobeep_num("Parse error"\ " line:", lnm)); inquote++; } else if (inquote > 0 && esc == 1) esc = 0; else inquote--; } else if (*prechr == '"' && inquote == 0) { return(dobeep_num("Parse error line:", lnm)); } endp = NULL; spc = 0; } else if (endp == NULL && (*p == ' ' || *p == '\t')) { if (inquote == 0) { *p = ' '; endp = p; spc++; if (begp != NULL) ns++; } esc = 0; } else if (*p == '\t' || *p == ' ') { if (inquote == 0) { *p = ' '; spc++; } esc = 0; } if (*p != '\t' && *p != ' ' && inquote == 0) lastchr = p; if (pctr == 0) { blkid++; expctr = 0; defnam = NULL; } prechr = p; } if (pctr != 0) { cleanup(); return(dobeep_num("Opening and closing parentheses error line:", lnm)); } if (ret == FALSE) cleanup(); else clearexp(); /* leave lists but remove expressions */ return (ret); } static int parse(char *begp, const char *par1, const char *par2, int blkid, int expctr, int elen, int ns) { char *regs; int ret = FALSE; if (strncmp(begp, "define", 6) == 0) { ret = parsdef(begp, par1, par2, blkid, expctr, elen); if (ret == TRUE || ret == FALSE) return (ret); } else if (strncmp(begp, "list", 4) == 0) return(parsval(begp, par1, par2, blkid, expctr, elen)); regs = "^exit$"; if (doregex(regs, begp)) return(exitinterpreter(NULL, NULL, FALSE)); /* mg function name regex */ regs = "^[A-Za-z-]+$"; if (doregex(regs, begp)) return(excline(begp, 0, 0)); /* Corner case 1 */ if (strncmp(begp, "global-set-key ", 15) == 0) /* function name as 2nd param screws up multiarg. */ return(excline(begp, 0, 0)); /* Corner case 2 */ if (strncmp(begp, "define-key ", 11) == 0) /* function name as 3rd param screws up multiarg. */ return(excline(begp, 0, 0)); return (parsexp(begp, par1, par2, blkid, expctr, elen)); } static int parsdef(char *begp, const char *par1, const char *par2, int blkid, int expctr, int elen) { char *regs; if ((defnam == NULL) && (expctr != 1)) return(dobeep_num("'define' incorrectly used line:", lnm)); /* Does the line have a incorrect variable 'define' like: */ /* (define i y z) */ regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]+.+[ ]+.+$"; if (doregex(regs, begp)) return(dobeep_num("Invalid use of define line:", lnm)); /* Does the line have a single variable 'define' like: */ /* (define i 0) */ regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]+.*$"; if (doregex(regs, begp)) { if (par1 == &lp && par2 == &rp && expctr == 1) return(founddef(begp, blkid, expctr, 1, elen)); return(dobeep_num("Invalid use of define line:", lnm)); } /* Does the line have '(define i(' */ regs = "^define[ ]+[A-Za-z][.0-9_A-Z+a-z-]*[ ]*$"; if (doregex(regs, begp)) { if (par1 == &lp && par2 == &lp && expctr == 1) return(founddef(begp, blkid, expctr, 0, elen)); return(dobeep_num("Invalid use of 'define' line:", lnm)); } /* Does the line have '(define (' */ regs = "^define$"; if (doregex(regs, begp)) { if (par1 == &lp && par2 == &lp && expctr == 1) return(foundfun(begp, expctr)); return(dobeep_num("Invalid use of 'define' line:", lnm)); } return (ABORT); } static int parsval(char *begp, const char *par1, const char *par2, int blkid, int expctr, int elen) { char *regs; /* Does the line have 'list' */ regs = "^list$"; if (doregex(regs, begp)) return(dobeep_num("Invalid use of list line:", lnm)); /* Does the line have a 'list' like: */ /* (list "a" "b") */ regs = "^list[ ]+.*$"; if (doregex(regs, begp)) { if (expctr == 1) return(dobeep_num("list with no-where to go.", lnm)); if (par1 == &lp && expctr > 1) return(foundlst(begp, blkid, expctr, elen)); return(dobeep_num("Invalid use of list line:", lnm)); } return (FALSE); } static int parsexp(char *begp, const char *par1, const char *par2, int blkid, int expctr, int elen) { struct expentry *e1 = NULL; PF funcp; char *cmdp, *fendp, *valp, *fname, *funb = NULL; int numparams, ret; cmdp = begp; fendp = strchr(cmdp, ' '); *fendp = '\0'; /* * If no extant mg command found, just return. */ if ((funcp = name_function(cmdp)) == NULL) return (dobeep_msgs("Unknown command:", cmdp)); numparams = numparams_function(funcp); if (numparams == 0) return (dobeep_msgs("Command takes no arguments:", cmdp)); if (numparams == -1) return (dobeep_msgs("Interactive command found:", cmdp)); if ((e1 = malloc(sizeof(struct expentry))) == NULL) { cleanup(); return (dobeep_msg("malloc Error")); } TAILQ_INSERT_HEAD(&ehead, e1, eentry); if ((e1->fun = strndup(cmdp, BUFSIZE)) == NULL) { cleanup(); return(dobeep_msg("strndup error")); } cmdp = e1->fun; fname = e1->fun; e1->funbuf[0] = '\0'; funb = e1->funbuf; e1->expctr = expctr; e1->blkid = blkid; /* need to think about these two */ e1->par1 = par1; e1->par2 = par2; *fendp = ' '; valp = fendp + 1; ret = expandvals(cmdp, valp, funb); if (!ret) return (ret); return (multiarg(fname, funb, numparams)); } /* * Pass a list of arguments to a function. */ static int multiarg(char *cmdp, char *argbuf, int numparams) { char excbuf[BUFSIZE]; char *argp, *p, *s = " "; char *regs; int spc, numspc; int fin, inquote; argp = argbuf; spc = 1; /* initially fake a space so we find first argument */ numspc = fin = inquote = 0; for (p = argbuf; *p != '\0'; p++) { if (*(p + 1) == '\0') fin = 1; if (*p != ' ') { if (*p == '"') { if (inquote == 1) inquote = 0; else inquote = 1; } if (spc == 1) if ((numspc % numparams) == 0) { argp = p; } spc = 0; } if ((*p == ' ' && inquote == 0) || fin) { if (spc == 1)/* || (numspc % numparams == 0))*/ continue; if ((numspc % numparams) != (numparams - 1)) { numspc++; continue; } if (*p == ' ') { *p = '\0'; /* terminate arg string */ } excbuf[0] = '\0'; regs = "[\"]+.*[\"]+"; if (!doregex(regs, argp)) { const char *errstr; strtonum(argp, 0, INT_MAX, &errstr); if (errstr != NULL) return (dobeep_msgs("Var not found:", argp)); } if (strlcpy(excbuf, cmdp, sizeof(excbuf)) >= sizeof(excbuf)) return (dobeep_msg("strlcpy error")); if (strlcat(excbuf, s, sizeof(excbuf)) >= sizeof(excbuf)) return (dobeep_msg("strlcat error")); if (strlcat(excbuf, argp, sizeof(excbuf)) >= sizeof(excbuf)) return (dobeep_msg("strlcat error")); excline(excbuf, 0, 0); if (fin) break; *p = ' '; /* unterminate arg string */ numspc++; spc = 1; } } return (TRUE); } /* * Is an item a value or a variable? */ static int isvar(char **argp, char **varbuf, int sizof) { struct varentry *v1 = NULL; if (SLIST_EMPTY(&varhead)) return (FALSE); #ifdef MGLOG mglog_isvar(*varbuf, *argp, sizof); #endif SLIST_FOREACH(v1, &varhead, entry) { if (strcmp(*argp, v1->v_name) == 0) { (void)(strlcpy(*varbuf, v1->v_buf, sizof) >= sizof); return (TRUE); } } return (FALSE); } static int foundfun(char *defstr, int expctr) { return (TRUE); } static int foundlst(char *defstr, int blkid, int expctr, int elen) { char *p; p = strstr(defstr, " "); p = skipwhite(p); expandvals(NULL, p, defnam); return (TRUE); } /* * 'define' strings follow the regex in parsdef(). */ static int founddef(char *defstr, int blkid, int expctr, int hasval, int elen) { struct varentry *vt, *v1 = NULL; char *p, *vnamep, *vendp = NULL, *valp; p = strstr(defstr, " "); /* move to first ' ' char. */ vnamep = skipwhite(p); /* find first char of var name. */ vendp = vnamep; /* now find the end of the define/list name */ while (1) { ++vendp; if (*vendp == ' ') break; } *vendp = '\0'; /* * Check list name is not an existing mg function. */ if (name_function(vnamep) != NULL) return(dobeep_msgs("Variable/function name clash:", vnamep)); if (!SLIST_EMPTY(&varhead)) { SLIST_FOREACH_SAFE(v1, &varhead, entry, vt) { if (strcmp(vnamep, v1->v_name) == 0) SLIST_REMOVE(&varhead, v1, varentry, entry); } } if ((v1 = malloc(sizeof(struct varentry))) == NULL) return (ABORT); SLIST_INSERT_HEAD(&varhead, v1, entry); if ((v1->v_name = strndup(vnamep, BUFSIZE)) == NULL) return(dobeep_msg("strndup error")); vnamep = v1->v_name; v1->v_count = 0; v1->v_vals = NULL; v1->v_buf[0] = '\0'; defnam = v1->v_buf; if (hasval) { valp = skipwhite(vendp + 1); expandvals(NULL, valp, defnam); defnam = NULL; } *vendp = ' '; return (TRUE); } static int expandvals(char *cmdp, char *valp, char *bp) { char excbuf[BUFSIZE], argbuf[BUFSIZE]; char contbuf[BUFSIZE], varbuf[BUFSIZE]; char *argp, *endp, *p, *v, *s = " "; char *regs; int spc, cnt; int sizof, fin, inquote; /* now find the first argument */ p = skipwhite(valp); if (strlcpy(argbuf, p, sizeof(argbuf)) >= sizeof(argbuf)) return (dobeep_msg("strlcpy error")); argp = argbuf; spc = 1; /* initially fake a space so we find first argument */ fin = inquote = cnt = spc = 0; for (p = argbuf; *p != '\0'; p++) { if (*(p + 1) == '\0') fin = 1; if (*p != ' ') { if (*p == '"') { if (inquote == 1) inquote = 0; else inquote = 1; } if (spc == 1) argp = p; spc = 0; } if ((*p == ' ' && inquote == 0) || fin) { if (spc == 1) continue; /* terminate arg string */ if (*p == ' ') { *p = '\0'; } endp = p + 1; excbuf[0] = '\0'; varbuf[0] = '\0'; contbuf[0] = '\0'; sizof = sizeof(varbuf); v = varbuf; regs = "[\"]+.*[\"]+"; if (doregex(regs, argp)) ; /* found quotes */ else if (isvar(&argp, &v, sizof)) { (void)(strlcat(varbuf, " ", sizof) >= sizof); *p = ' '; (void)(strlcpy(contbuf, endp, sizeof(contbuf)) >= sizeof(contbuf)); (void)(strlcat(varbuf, contbuf, sizof) >= sizof); argbuf[0] = ' '; argbuf[1] = '\0'; (void)(strlcat(argbuf, varbuf, sizof) >= sizof); p = argp = argbuf; spc = 1; fin = 0; continue; } else { const char *errstr; strtonum(argp, 0, INT_MAX, &errstr); if (errstr != NULL) return (dobeep_msgs("Var not found:", argp)); } #ifdef MGLOG mglog_misc("x|%s|%p|%d|\n", bp, defnam, BUFSIZE); #endif if (*bp != '\0') { if (strlcat(bp, s, BUFSIZE) >= BUFSIZE) return (dobeep_msg("strlcat error")); } if (strlcat(bp, argp, BUFSIZE) >= BUFSIZE) { return (dobeep_msg("strlcat error")); } /* v1->v_count++;*/ if (fin) break; *p = ' '; /* unterminate arg string */ spc = 1; } } return (TRUE); } /* * Finished with buffer evaluation, so clean up any vars. * Perhaps keeps them in mg even after use,... */ /*static int clearvars(void) { struct varentry *v1 = NULL; while (!SLIST_EMPTY(&varhead)) { v1 = SLIST_FIRST(&varhead); SLIST_REMOVE_HEAD(&varhead, entry); free(v1->v_name); free(v1); } return (FALSE); } */ /* * Finished with block evaluation, so clean up any expressions. */ static void clearexp(void) { struct expentry *e1 = NULL; while (!TAILQ_EMPTY(&ehead)) { e1 = TAILQ_FIRST(&ehead); TAILQ_REMOVE(&ehead, e1, eentry); free(e1->fun); free(e1); } return; } /* * Cleanup before leaving. */ void cleanup(void) { defnam = NULL; clearexp(); /* clearvars();*/ } /* * Test a string against a regular expression. */ static int doregex(char *r, char *e) { regex_t regex_buff; if (regcomp(®ex_buff, r, REG_EXTENDED)) { regfree(®ex_buff); return(dobeep_num("Regex compilation error line:", lnm)); } if (!regexec(®ex_buff, e, 0, NULL, 0)) { regfree(®ex_buff); return(TRUE); } regfree(®ex_buff); return(FALSE); } /* * Display a message so it is apparent that this is the method which stopped * execution. */ static int exitinterpreter(char *ptr, char *dobuf, int dosiz) { cleanup(); if (batch == 0) return(dobeep_msg("Interpreter exited via exit command.")); return(FALSE); } /* * All code below commented out (until end of file). * * Need to think about how interpreter functions are done. * Probably don't have a choice with string-append(). static int getenvironmentvariable(char *, char *, int); static int stringappend(char *, char *, int); typedef int (*PFI)(char *, char *, int); struct ifunmap { PFI fn_funct; const char *fn_name; struct ifunmap *fn_next; }; static struct ifunmap *ifuns; static struct ifunmap ifunctnames[] = { {exitinterpreter, "exit"}, {getenvironmentvariable, "get-environment-variable"}, {stringappend, "string-append"}, {NULL, NULL} }; void ifunmap_init(void) { struct ifunmap *fn; for (fn = ifunctnames; fn->fn_name != NULL; fn++) { fn->fn_next = ifuns; ifuns = fn; } } PFI name_ifun(const char *ifname) { struct ifunmap *fn; for (fn = ifuns; fn != NULL; fn = fn->fn_next) { if (strcmp(fn->fn_name, ifname) == 0) return (fn->fn_funct); } return (NULL); } int dofunc(char **ifname, char **tmpbuf, int sizof) { PFI fnc; char *p, *tmp; p = strstr(*ifname, " "); *p = '\0'; fnc = name_ifun(*ifname); if (fnc == NULL) return (FALSE); *p = ' '; tmp = *tmpbuf; fnc(p, tmp, sizof); return (TRUE); } static int getenvironmentvariable(char *ptr, char *dobuf, int dosiz) { char *t; char *tmp; const char *q = "\""; t = skipwhite(ptr); if (t[0] == *q || t[strlen(t) - 1] == *q) return (dobeep_msgs("Please remove '\"' around:", t)); if ((tmp = getenv(t)) == NULL || *tmp == '\0') return(dobeep_msgs("Envar not found:", t)); dobuf[0] = '\0'; if (strlcat(dobuf, q, dosiz) >= dosiz) return (dobeep_msg("strlcat error")); if (strlcat(dobuf, tmp, dosiz) >= dosiz) return (dobeep_msg("strlcat error")); if (strlcat(dobuf, q, dosiz) >= dosiz) return (dobeep_msg("strlcat error")); return (TRUE); } static int stringappend(char *ptr, char *dobuf, int dosiz) { char varbuf[BUFSIZE], funbuf[BUFSIZE]; char *p, *f, *v, *vendp; int sizof, fin = 0; varbuf[0] = funbuf[0] = '\0'; f = funbuf; v = varbuf; sizof = sizeof(varbuf); *dobuf = '\0'; p = skipwhite(ptr); while (*p != '\0') { vendp = p; while (1) { if (*vendp == ' ') { break; } else if (*vendp == '\0') { fin = 1; break; } ++vendp; } *vendp = '\0'; if (isvar(&p, &v, sizof)) { if (v[0] == '"' && v[strlen(v) - 1] == '"' ) { v[strlen(v) - 1] = '\0'; v = v + 1; } if (strlcat(f, v, sizof) >= sizof) return (dobeep_msg("strlcat error")); } else { if (p[0] == '"' && p[strlen(p) - 1] == '"' ) { p[strlen(p) - 1] = '\0'; p = p + 1; } if (strlcat(f, p, sizof) >= sizof) return (dobeep_msg("strlcat error")); } if (fin) break; vendp++; if (*vendp == '\0') break; p = skipwhite(vendp); } (void)snprintf(dobuf, dosiz, "\"%s\"", f); return (TRUE); } Index: main.c =================================================================== RCS file: /cvs/src/usr.bin/mg/main.c,v retrieving revision 1.89 diff -u -p -u -p -r1.89 main.c --- main.c 20 Mar 2021 09:00:49 -0000 1.89 +++ main.c 12 Apr 2021 17:58:52 -0000 @@ -133,10 +133,12 @@ main(int argc, char **argv) extern void grep_init(void); extern void cmode_init(void); extern void dired_init(void); + extern void ifunmap_init(void); dired_init(); grep_init(); cmode_init(); + ifunmap_init(); } */