/* $NetBSD: expand.c,v 1.117 2017/06/18 07:50:46 kre Exp $ */ /*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #ifndef lint #if 0 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; #else __RCSID("$NetBSD: expand.c,v 1.117 2017/06/18 07:50:46 kre Exp $"); #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #include /* * Routines to expand arguments to commands. We have to deal with * backquotes, shell variables, and file metacharacters. */ #include "shell.h" #include "main.h" #include "nodes.h" #include "eval.h" #include "expand.h" #include "syntax.h" #include "arithmetic.h" #include "parser.h" #include "jobs.h" #include "options.h" #include "builtins.h" #include "var.h" #include "input.h" #include "output.h" #include "memalloc.h" #include "error.h" #include "mystring.h" #include "show.h" /* * Structure specifying which parts of the string should be searched * for IFS characters. */ struct ifsregion { struct ifsregion *next; /* next region in list */ int begoff; /* offset of start of region */ int endoff; /* offset of end of region */ int inquotes; /* search for nul bytes only */ }; char *expdest; /* output of current string */ struct nodelist *argbackq; /* list of back quote expressions */ struct ifsregion ifsfirst; /* first struct in list of ifs regions */ struct ifsregion *ifslastp; /* last struct in list */ struct arglist exparg; /* holds expanded arg list */ STATIC const char *argstr(const char *, int); STATIC const char *exptilde(const char *, int); STATIC void expbackq(union node *, int, int); STATIC const char *expari(const char *); STATIC int subevalvar(const char *, const char *, int, int, int); STATIC int subevalvar_trim(const char *, int, int, int, int, int); STATIC const char *evalvar(const char *, int); STATIC int varisset(const char *, int); STATIC void varvalue(const char *, int, int, int); STATIC void recordregion(int, int, int); STATIC void removerecordregions(int); STATIC void ifsbreakup(char *, struct arglist *); STATIC void ifsfree(void); STATIC void expandmeta(struct strlist *, int); STATIC void expmeta(char *, char *); STATIC void addfname(char *); STATIC struct strlist *expsort(struct strlist *); STATIC struct strlist *msort(struct strlist *, int); STATIC int patmatch(const char *, const char *, int); STATIC char *cvtnum(int, char *); static int collate_range_cmp(wchar_t, wchar_t); STATIC void add_args(struct strlist *); STATIC void rmescapes_nl(char *); /* * Expand shell variables and backquotes inside a here document. */ void expandhere(union node *arg, int fd) { herefd = fd; expandarg(arg, NULL, 0); xwrite(fd, stackblock(), expdest - stackblock()); } static int collate_range_cmp(wchar_t c1, wchar_t c2) { wchar_t s1[2], s2[2]; s1[0] = c1; s1[1] = L'\0'; s2[0] = c2; s2[1] = L'\0'; return (wcscoll(s1, s2)); } /* * Perform variable substitution and command substitution on an argument, * placing the resulting list of arguments in arglist. If EXP_FULL is true, * perform splitting and file name expansion. When arglist is NULL, perform * here document expansion. */ void expandarg(union node *arg, struct arglist *arglist, int flag) { struct strlist *sp; char *p; CTRACE(DBG_EXPAND, ("expandarg(fl=%#x)\n", flag)); if (fflag) /* no filename expandsion */ flag &= ~EXP_GLOB; argbackq = arg->narg.backquote; STARTSTACKSTR(expdest); ifsfirst.next = NULL; ifslastp = NULL; line_number = arg->narg.lineno; argstr(arg->narg.text, flag); if (arglist == NULL) { STACKSTRNUL(expdest); CTRACE(DBG_EXPAND, ("expandarg: no arglist, done (%d) \"%s\"\n", expdest - stackblock(), stackblock())); return; /* here document expanded */ } STPUTC('\0', expdest); CTRACE(DBG_EXPAND, ("expandarg: arglist got (%d) \"%s\"\n", expdest - stackblock() - 1, stackblock())); p = grabstackstr(expdest); exparg.lastp = &exparg.list; /* * TODO - EXP_REDIR */ if (flag & EXP_SPLIT) { ifsbreakup(p, &exparg); *exparg.lastp = NULL; exparg.lastp = &exparg.list; if (flag & EXP_GLOB) expandmeta(exparg.list, flag); else add_args(exparg.list); } else { if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ rmescapes(p); sp = stalloc(sizeof(*sp)); sp->text = p; *exparg.lastp = sp; exparg.lastp = &sp->next; } ifsfree(); *exparg.lastp = NULL; if (exparg.list) { *arglist->lastp = exparg.list; arglist->lastp = exparg.lastp; } } /* * Perform variable and command substitution. * If EXP_GLOB is set, output CTLESC characters to allow for further processing. * If EXP_SPLIT is set, remember location of result for later, * Otherwise treat $@ like $* since no splitting will be performed. */ STATIC const char * argstr(const char *p, int flag) { char c; int quotes = flag & (EXP_GLOB | EXP_CASE | EXP_REDIR); /* do CTLESC */ int firsteq = 1; const char *ifs = NULL; int ifs_split = EXP_IFS_SPLIT; if (flag & EXP_IFS_SPLIT) ifs = ifsval(); CTRACE(DBG_EXPAND, ("argstr(\"%s\", %#x) quotes=%#x\n", p,flag,quotes)); if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) p = exptilde(p, flag); for (;;) { switch (c = *p++) { case '\0': STACKSTRNUL(expdest); VTRACE(DBG_EXPAND, ("argstr returning at \"\" " "added \"%s\" to expdest\n", stackblock())); return p - 1; case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */ case CTLENDARI: /* end of a $(( )) string */ STACKSTRNUL(expdest); VTRACE(DBG_EXPAND, ("argstr returning at \"%.6s\"..." " after %2.2X; added \"%s\" to expdest\n", p, (c&0xff), stackblock())); return p; case CTLQUOTEMARK: /* "$@" syntax adherence hack */ if (p[0] == CTLVAR && p[1] & VSQUOTE && p[2] == '@' && p[3] == '=') break; if ((flag & EXP_SPLIT) != 0) STPUTC(c, expdest); ifs_split = 0; break; case CTLNONL: if (flag & EXP_NL) STPUTC(c, expdest); line_number++; break; case CTLQUOTEEND: ifs_split = EXP_IFS_SPLIT; break; case CTLESC: if (quotes) STPUTC(c, expdest); c = *p++; STPUTC(c, expdest); if (c == '\n') /* should not happen, but ... */ line_number++; break; case CTLVAR: { #ifdef DEBUG unsigned int pos = expdest - stackblock(); #endif p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split)); STACKSTRNUL(expdest); VTRACE(DBG_EXPAND, ("argstr evalvar " "added \"%s\" to expdest\n", stackblock() + pos)); break; } case CTLBACKQ: case CTLBACKQ|CTLQUOTE: { #ifdef DEBUG unsigned int pos = expdest - stackblock(); #endif expbackq(argbackq->n, c & CTLQUOTE, flag); argbackq = argbackq->next; STACKSTRNUL(expdest); VTRACE(DBG_EXPAND, ("argstr expbackq added \"%s\" " "to expdest\n", stackblock() + pos)); break; } case CTLARI: { #ifdef DEBUG unsigned int pos = expdest - stackblock(); #endif p = expari(p); STACKSTRNUL(expdest); VTRACE(DBG_EXPAND, ("argstr expari " "+ \"%s\" to expdest p=\"%.5s...\"\n", stackblock() + pos, p)); break; } case ':': case '=': /* * sort of a hack - expand tildes in variable * assignments (after the first '=' and after ':'s). */ STPUTC(c, expdest); if (flag & EXP_VARTILDE && *p == '~') { if (c == '=') { if (firsteq) firsteq = 0; else break; } p = exptilde(p, flag); } break; default: if (c == '\n') line_number++; STPUTC(c, expdest); if (flag & ifs_split && strchr(ifs, c) != NULL) { /* We need to get the output split here... */ recordregion(expdest - stackblock() - 1, expdest - stackblock(), 0); } break; } } } STATIC const char * exptilde(const char *p, int flag) { char c; const char *startp = p; struct passwd *pw; const char *home; int quotes = flag & (EXP_GLOB | EXP_CASE); char *user; struct stackmark smark; #ifdef DEBUG unsigned int offs = expdest - stackblock(); #endif setstackmark(&smark); user = stackblock(); /* we will just borrow top of stack */ while ((c = *++p) != '\0') { switch(c) { case CTLESC: /* any of these occurring */ case CTLVAR: /* means ~ expansion */ case CTLBACKQ: /* does not happen at all */ case CTLBACKQ | CTLQUOTE: case CTLARI: /* just leave original unchanged */ case CTLENDARI: case CTLQUOTEMARK: case CTLENDVAR: case '\n': popstackmark(&smark); return (startp); case CTLNONL: continue; case ':': if (flag & EXP_VARTILDE) goto done; break; case '/': goto done; } STPUTC(c, user); } done: STACKSTRNUL(user); user = stackblock(); /* to start of collected username */ CTRACE(DBG_EXPAND, ("exptilde, found \"~%s\"", user)); if (*user == '\0') { home = lookupvar("HOME"); /* * if HOME is unset, results are unspecified... * we used to just leave the ~ unchanged, but * (some) other shells do ... and this seems more useful. */ if (home == NULL && (pw = getpwuid(getuid())) != NULL) home = pw->pw_dir; } else if ((pw = getpwnam(user)) == NULL) { /* * If user does not exist, results are undefined. * so we can abort() here if we want, but let's not! */ home = NULL; } else home = pw->pw_dir; VTRACE(DBG_EXPAND, (" ->\"%s\"", home ? home : "<>")); popstackmark(&smark); /* now expdest is valid again */ /* * Posix XCU 2.6.1: The value of $HOME (for ~) or the initial * working directory from getpwnam() for ~user * Nothing there about "except if a null string". So do what it wants. */ if (home == NULL /* || *home == '\0' */) { CTRACE(DBG_EXPAND, (": returning unused \"%s\"\n", startp)); return startp; } while ((c = *home++) != '\0') { if (quotes && SQSYNTAX[(int)c] == CCTL) STPUTC(CTLESC, expdest); STPUTC(c, expdest); } CTRACE(DBG_EXPAND, (": added %d \"%.*s\" returning \"%s\"\n", expdest - stackblock() - offs, expdest - stackblock() - offs, stackblock() + offs, p)); return (p); } STATIC void removerecordregions(int endoff) { VTRACE(DBG_EXPAND, ("removerecordregions(%d):", endoff)); if (ifslastp == NULL) { VTRACE(DBG_EXPAND, (" none\n", endoff)); return; } if (ifsfirst.endoff > endoff) { VTRACE(DBG_EXPAND, (" first(%d)", ifsfirst.endoff)); while (ifsfirst.next != NULL) { struct ifsregion *ifsp; INTOFF; ifsp = ifsfirst.next->next; ckfree(ifsfirst.next); ifsfirst.next = ifsp; INTON; } if (ifsfirst.begoff > endoff) ifslastp = NULL; else { VTRACE(DBG_EXPAND,("->(%d,%d)",ifsfirst.begoff,endoff)); ifslastp = &ifsfirst; ifsfirst.endoff = endoff; } VTRACE(DBG_EXPAND, ("\n")); return; } ifslastp = &ifsfirst; while (ifslastp->next && ifslastp->next->begoff < endoff) ifslastp=ifslastp->next; VTRACE(DBG_EXPAND, (" found(%d,%d)", ifslastp->begoff,ifslastp->endoff)); while (ifslastp->next != NULL) { struct ifsregion *ifsp; INTOFF; ifsp = ifslastp->next->next; ckfree(ifslastp->next); ifslastp->next = ifsp; INTON; } if (ifslastp->endoff > endoff) ifslastp->endoff = endoff; VTRACE(DBG_EXPAND, ("->(%d,%d)", ifslastp->begoff,ifslastp->endoff)); } /* * Expand arithmetic expression. * * In this incarnation, we start at the beginning (yes, "Let's start at the * very beginning. A very good place to start.") and collect the expression * until the end - which means expanding anything contained within. * * Fortunately, argstr() just happens to do that for us... */ STATIC const char * expari(const char *p) { char *q, *start; intmax_t result; int adjustment; int begoff; int quoted; struct stackmark smark; /* ifsfree(); */ /* * SPACE_NEEDED is enough for all possible digits (rounded up) * plus possible "-", and the terminating '\0', hence, plus 2 * * The calculation produces the number of bytes needed to * represent the biggest possible value, in octal. We only * generate decimal, which takes (often) less digits (never more) * so this is safe, if occasionally slightly wasteful. */ #define SPACE_NEEDED ((int)((sizeof(intmax_t) * CHAR_BIT + 2) / 3 + 2)) quoted = *p++ == '"'; begoff = expdest - stackblock(); VTRACE(DBG_EXPAND, ("expari%s: \"%s\" begoff %d\n", quoted ? "(quoted)" : "", p, begoff)); p = argstr(p, EXP_NL); /* expand $(( )) string */ STPUTC('\0', expdest); start = stackblock() + begoff; removerecordregions(begoff); /* nothing there is kept */ rmescapes_nl(start); /* convert CRTNONL back into \n's */ setstackmark(&smark); q = grabstackstr(expdest); /* keep the expression while eval'ing */ result = arith(start, line_number); popstackmark(&smark); /* return the stack to before grab */ start = stackblock() + begoff; /* block may have moved */ adjustment = expdest - start; STADJUST(-adjustment, expdest); /* remove the argstr() result */ CHECKSTRSPACE(SPACE_NEEDED, expdest); /* nb: stack block might move */ fmtstr(expdest, SPACE_NEEDED, "%"PRIdMAX, result); for (q = expdest; *q++ != '\0'; ) /* find end of what we added */ ; if (quoted == 0) /* allow weird splitting */ recordregion(begoff, begoff + q - 1 - expdest, 0); adjustment = q - expdest - 1; STADJUST(adjustment, expdest); /* move expdest to end */ VTRACE(DBG_EXPAND, ("expari: adding %d \"%s\", returning \"%.5s...\"\n", adjustment, stackblock() + begoff, p)); return p; } /* * Expand stuff in backwards quotes (these days, any command substitution). */ STATIC void expbackq(union node *cmd, int quoted, int flag) { struct backcmd in; int i; char buf[128]; char *p; char *dest = expdest; /* expdest may be reused by eval, use an alt */ struct ifsregion saveifs, *savelastp; struct nodelist *saveargbackq; char lastc; int startloc = dest - stackblock(); char const *syntax = quoted? DQSYNTAX : BASESYNTAX; int saveherefd; int quotes = flag & (EXP_GLOB | EXP_CASE); int nnl; struct stackmark smark; VTRACE(DBG_EXPAND, ("expbackq( ..., q=%d flag=%#x) have %d\n", quoted, flag, startloc)); INTOFF; saveifs = ifsfirst; savelastp = ifslastp; saveargbackq = argbackq; saveherefd = herefd; herefd = -1; setstackmark(&smark); /* preserve the stack */ p = grabstackstr(dest); /* save what we have there currently */ evalbackcmd(cmd, &in); /* evaluate the $( ) tree (using stack) */ popstackmark(&smark); /* and return stack to when we entered */ ifsfirst = saveifs; ifslastp = savelastp; argbackq = saveargbackq; herefd = saveherefd; p = in.buf; /* now extract the results */ nnl = 0; /* dropping trailing \n's */ for (;;) { if (--in.nleft < 0) { if (in.fd < 0) break; while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR) continue; VTRACE(DBG_EXPAND, ("expbackq: read returns %d\n", i)); if (i <= 0) break; p = buf; in.nleft = i - 1; } lastc = *p++; if (lastc != '\0') { if (lastc == '\n') /* don't save \n yet */ nnl++; /* it might be trailing */ else { /* * We have something other than \n * * Before saving it, we need to insert * any \n's that we have just skipped. */ /* XXX * this hack is just because our * CHECKSTRSPACE() is lazy, and only * ever grows the stack once, even * if that does not allocate the space * we requested. ie: safe for small * requests, but not large ones. * FIXME someday... */ if (nnl < 20) { CHECKSTRSPACE(nnl + 2, dest); while (nnl > 0) { nnl--; USTPUTC('\n', dest); } } else { /* The slower, safer, way */ while (nnl > 0) { nnl--; STPUTC('\n', dest); } CHECKSTRSPACE(2, dest); } if (quotes && syntax[(int)lastc] == CCTL) USTPUTC(CTLESC, dest); USTPUTC(lastc, dest); } } } if (in.fd >= 0) close(in.fd); if (in.buf) ckfree(in.buf); if (in.jp) back_exitstatus = waitforjob(in.jp); if (quoted == 0) recordregion(startloc, dest - stackblock(), 0); CTRACE(DBG_EXPAND, ("evalbackq: size=%d: \"%.*s\"\n", (int)((dest - stackblock()) - startloc), (int)((dest - stackblock()) - startloc), stackblock() + startloc)); expdest = dest; /* all done, expdest is all ours again */ INTON; } STATIC int subevalvar(const char *p, const char *str, int subtype, int startloc, int varflags) { char *startp; int saveherefd = herefd; struct nodelist *saveargbackq = argbackq; int amount; herefd = -1; VTRACE(DBG_EXPAND, ("subevalvar(%d) \"%.20s\" ${%.*s} sloc=%d vf=%x\n", subtype, p, p-str, str, startloc, varflags)); argstr(p, EXP_TILDE); STACKSTRNUL(expdest); herefd = saveherefd; argbackq = saveargbackq; startp = stackblock() + startloc; switch (subtype) { case VSASSIGN: setvar(str, startp, 0); amount = startp - expdest; /* remove what argstr added */ STADJUST(amount, expdest); varflags &= ~VSNUL; /*XXX Huh? What's that achieve? */ return 1; /* go back and eval var again */ case VSQUESTION: if (*p != CTLENDVAR) { outfmt(&errout, "%s\n", startp); error(NULL); } error("%.*s: parameter %snot set", (int)(p - str - 1), str, (varflags & VSNUL) ? "null or " : nullstr); /* NOTREACHED */ default: abort(); } } STATIC int subevalvar_trim(const char *p, int strloc, int subtype, int startloc, int varflags, int quotes) { char *startp; char *str; char *loc = NULL; char *q; int c = 0; int saveherefd = herefd; struct nodelist *saveargbackq = argbackq; int amount; herefd = -1; switch (subtype) { case VSTRIMLEFT: case VSTRIMLEFTMAX: case VSTRIMRIGHT: case VSTRIMRIGHTMAX: break; default: abort(); break; } VTRACE(DBG_EXPAND, ("subevalvar_trim(\"%.9s\", STR@%d, SUBT=%d, start@%d, vf=%x, q=%x)\n", p, strloc, subtype, startloc, varflags, quotes)); argstr(p, (varflags & (VSQUOTE|VSPATQ)) == VSQUOTE ? 0 : EXP_CASE); STACKSTRNUL(expdest); herefd = saveherefd; argbackq = saveargbackq; startp = stackblock() + startloc; str = stackblock() + strloc; switch (subtype) { case VSTRIMLEFT: for (loc = startp; loc < str; loc++) { c = *loc; *loc = '\0'; if (patmatch(str, startp, quotes)) goto recordleft; *loc = c; if (quotes && *loc == CTLESC) loc++; } return 0; case VSTRIMLEFTMAX: for (loc = str - 1; loc >= startp;) { c = *loc; *loc = '\0'; if (patmatch(str, startp, quotes)) goto recordleft; *loc = c; loc--; if (quotes && loc > startp && *(loc - 1) == CTLESC) { for (q = startp; q < loc; q++) if (*q == CTLESC) q++; if (q > loc) loc--; } } return 0; case VSTRIMRIGHT: for (loc = str - 1; loc >= startp;) { if (patmatch(str, loc, quotes)) goto recordright; loc--; if (quotes && loc > startp && *(loc - 1) == CTLESC) { for (q = startp; q < loc; q++) if (*q == CTLESC) q++; if (q > loc) loc--; } } return 0; case VSTRIMRIGHTMAX: for (loc = startp; loc < str - 1; loc++) { if (patmatch(str, loc, quotes)) goto recordright; if (quotes && *loc == CTLESC) loc++; } return 0; default: abort(); } recordleft: *loc = c; amount = ((str - 1) - (loc - startp)) - expdest; STADJUST(amount, expdest); while (loc != str - 1) *startp++ = *loc++; return 1; recordright: amount = loc - expdest; STADJUST(amount, expdest); STPUTC('\0', expdest); STADJUST(-1, expdest); return 1; } /* * Expand a variable, and return a pointer to the next character in the * input string. */ STATIC const char * evalvar(const char *p, int flag) { int subtype; int varflags; const char *var; char *val; int patloc; int c; int set; int special; int startloc; int varlen; int apply_ifs; int quotes = flag & (EXP_GLOB | EXP_CASE | EXP_REDIR); varflags = (unsigned char)*p++; subtype = varflags & VSTYPE; var = p; special = !is_name(*p); p = strchr(p, '=') + 1; CTRACE(DBG_EXPAND, ("evalvar \"%.*s\", flag=%#X quotes=%#X vf=%#X subtype=%X\n", p - var - 1, var, flag, quotes, varflags, subtype)); again: /* jump here after setting a variable with ${var=text} */ if (varflags & VSLINENO) { if (line_num.flags & VUNSET) { set = 0; val = NULL; } else { set = 1; special = p - var; val = NULL; } } else if (special) { set = varisset(var, varflags & VSNUL); val = NULL; } else { val = lookupvar(var); if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { val = NULL; set = 0; } else set = 1; } varlen = 0; startloc = expdest - stackblock(); if (!set && uflag && *var != '@' && *var != '*') { switch (subtype) { case VSNORMAL: case VSTRIMLEFT: case VSTRIMLEFTMAX: case VSTRIMRIGHT: case VSTRIMRIGHTMAX: case VSLENGTH: error("%.*s: parameter not set", (int)(p - var - 1), var); /* NOTREACHED */ } } if (set && subtype != VSPLUS) { /* insert the value of the variable */ if (special) { if (varflags & VSLINENO) { /* * The LINENO hack (expansion part) */ while (--special > 0) { /* not needed, it is a number... if (quotes && syntax[(int)*var] == CCTL) STPUTC(CTLESC, expdest); */ STPUTC(*var++, expdest); } } else varvalue(var, varflags&VSQUOTE, subtype, flag); if (subtype == VSLENGTH) { varlen = expdest - stackblock() - startloc; STADJUST(-varlen, expdest); } } else { char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX : BASESYNTAX; if (subtype == VSLENGTH) { for (;*val; val++) varlen++; } else { while (*val) { if (quotes && syntax[(int)*val] == CCTL) STPUTC(CTLESC, expdest); STPUTC(*val++, expdest); } } } } if (flag & EXP_IN_QUOTES) apply_ifs = 0; else if (varflags & VSQUOTE) { if (*var == '@' && shellparam.nparam != 1) apply_ifs = 1; else { /* * Mark so that we don't apply IFS if we recurse through * here expanding $bar from "${foo-$bar}". */ flag |= EXP_IN_QUOTES; apply_ifs = 0; } } else apply_ifs = 1; switch (subtype) { case VSLENGTH: expdest = cvtnum(varlen, expdest); break; case VSNORMAL: break; case VSPLUS: set = !set; /* FALLTHROUGH */ case VSMINUS: if (!set) { argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0)); /* * ${x-a b c} doesn't get split, but removing the * 'apply_ifs = 0' apparently breaks ${1+"$@"}.. * ${x-'a b' c} should generate 2 args. */ if (*p != CTLENDVAR) /* We should have marked stuff already */ apply_ifs = 0; } break; case VSTRIMLEFT: case VSTRIMLEFTMAX: case VSTRIMRIGHT: case VSTRIMRIGHTMAX: if (!set) { set = 1; /* allow argbackq to be advanced if needed */ break; } /* * Terminate the string and start recording the pattern * right after it */ STPUTC('\0', expdest); patloc = expdest - stackblock(); if (subevalvar_trim(p, patloc, subtype, startloc, varflags, quotes) == 0) { int amount = (expdest - stackblock() - patloc) + 1; STADJUST(-amount, expdest); } /* Remove any recorded regions beyond start of variable */ removerecordregions(startloc); apply_ifs = 1; break; case VSASSIGN: case VSQUESTION: if (set) break; if (subevalvar(p, var, subtype, startloc, varflags)) { /* if subevalvar() returns, it always returns 1 */ varflags &= ~VSNUL; /* * Remove any recorded regions beyond * start of variable */ removerecordregions(startloc); goto again; } apply_ifs = 0; /* never executed */ break; default: abort(); } if (apply_ifs) recordregion(startloc, expdest - stackblock(), varflags & VSQUOTE); if (subtype != VSNORMAL) { /* skip to end of alternative */ int nesting = 1; for (;;) { if ((c = *p++) == CTLESC) p++; else if (c == CTLNONL) ; else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { if (set) argbackq = argbackq->next; } else if (c == CTLVAR) { if ((*p++ & VSTYPE) != VSNORMAL) nesting++; } else if (c == CTLENDVAR) { if (--nesting == 0) break; } } } return p; } /* * Test whether a special parameter is set. */ STATIC int varisset(const char *name, int nulok) { if (*name == '!') return backgndpid != -1; else if (*name == '@' || *name == '*') { if (*shellparam.p == NULL) return 0; if (nulok) { char **av; for (av = shellparam.p; *av; av++) if (**av != '\0') return 1; return 0; } } else if (is_digit(*name)) { char *ap; long num; /* * handle overflow sensibly (the *ap tests should never fail) */ errno = 0; num = strtol(name, &ap, 10); if (errno != 0 || (*ap != '\0' && *ap != '=')) return 0; if (num == 0) ap = arg0; else if (num > shellparam.nparam) return 0; else ap = shellparam.p[num - 1]; if (nulok && (ap == NULL || *ap == '\0')) return 0; } return 1; } /* * Add the value of a specialized variable to the stack string. */ STATIC void varvalue(const char *name, int quoted, int subtype, int flag) { int num; char *p; int i; char sep; char **ap; char const *syntax; if (subtype == VSLENGTH) /* no magic required ... */ flag &= ~EXP_FULL; #define STRTODEST(p) \ do {\ if (flag & (EXP_GLOB | EXP_CASE) && subtype != VSLENGTH) { \ syntax = quoted? DQSYNTAX : BASESYNTAX; \ while (*p) { \ if (syntax[(int)*p] == CCTL) \ STPUTC(CTLESC, expdest); \ STPUTC(*p++, expdest); \ } \ } else \ while (*p) \ STPUTC(*p++, expdest); \ } while (0) switch (*name) { case '$': num = rootpid; break; case '?': num = exitstatus; break; case '#': num = shellparam.nparam; break; case '!': num = backgndpid; break; case '-': for (i = 0; i < option_flags; i++) { if (optlist[optorder[i]].val) STPUTC(optlist[optorder[i]].letter, expdest); } return; case '@': if (flag & EXP_SPLIT && quoted) { for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { STRTODEST(p); if (*ap) /* A NUL separates args inside "" */ STPUTC('\0', expdest); } return; } /* fall through */ case '*': sep = ifsval()[0]; for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { STRTODEST(p); if (!*ap) break; if (sep) STPUTC(sep, expdest); else if ((flag & (EXP_SPLIT|EXP_IN_QUOTES)) == EXP_SPLIT && !quoted && **ap != '\0') STPUTC('\0', expdest); } return; default: if (is_digit(*name)) { long lnum; errno = 0; lnum = strtol(name, &p, 10); if (errno != 0 || (*p != '\0' && *p != '=')) return; if (lnum == 0) p = arg0; else if (lnum > 0 && lnum <= shellparam.nparam) p = shellparam.p[lnum - 1]; else return; STRTODEST(p); } return; } /* * only the specials with an int value arrive here */ expdest = cvtnum(num, expdest); } /* * Record the fact that we have to scan this region of the * string for IFS characters. */ STATIC void recordregion(int start, int end, int inquotes) { struct ifsregion *ifsp; VTRACE(DBG_EXPAND, ("recordregion(%d,%d,%d)\n", start, end, inquotes)); if (ifslastp == NULL) { ifsp = &ifsfirst; } else { if (ifslastp->endoff == start && ifslastp->inquotes == inquotes) { /* extend previous area */ ifslastp->endoff = end; return; } ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); ifslastp->next = ifsp; } ifslastp = ifsp; ifslastp->next = NULL; ifslastp->begoff = start; ifslastp->endoff = end; ifslastp->inquotes = inquotes; } /* * Break the argument string into pieces based upon IFS and add the * strings to the argument list. The regions of the string to be * searched for IFS characters have been stored by recordregion. */ STATIC void ifsbreakup(char *string, struct arglist *arglist) { struct ifsregion *ifsp; struct strlist *sp; char *start; char *p; char *q; const char *ifs; const char *ifsspc; int had_param_ch = 0; start = string; VTRACE(DBG_EXPAND, ("ifsbreakup(\"%s\")", string)); /* misses \0's */ if (ifslastp == NULL) { /* Return entire argument, IFS doesn't apply to any of it */ VTRACE(DBG_EXPAND, ("no regions\n", string)); sp = stalloc(sizeof(*sp)); sp->text = start; *arglist->lastp = sp; arglist->lastp = &sp->next; return; } ifs = ifsval(); for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { p = string + ifsp->begoff; VTRACE(DBG_EXPAND, (" !%.*s!(%d)", ifsp->endoff-ifsp->begoff, p, ifsp->endoff-ifsp->begoff)); while (p < string + ifsp->endoff) { had_param_ch = 1; q = p; if (*p == CTLNONL) { p++; continue; } if (*p == CTLESC) p++; if (ifsp->inquotes) { /* Only NULs (should be from "$@") end args */ if (*p != 0) { p++; continue; } ifsspc = NULL; VTRACE(DBG_EXPAND, (" \\0 nxt:\"%s\" ", p)); } else { if (!strchr(ifs, *p)) { p++; continue; } had_param_ch = 0; ifsspc = strchr(" \t\n", *p); /* Ignore IFS whitespace at start */ if (q == start && ifsspc != NULL) { p++; start = p; continue; } } /* Save this argument... */ *q = '\0'; VTRACE(DBG_EXPAND, ("<%s>", start)); sp = stalloc(sizeof(*sp)); sp->text = start; *arglist->lastp = sp; arglist->lastp = &sp->next; p++; if (ifsspc != NULL) { /* Ignore further trailing IFS whitespace */ for (; p < string + ifsp->endoff; p++) { q = p; if (*p == CTLNONL) continue; if (*p == CTLESC) p++; if (strchr(ifs, *p) == NULL) { p = q; break; } if (strchr(" \t\n", *p) == NULL) { p++; break; } } } start = p; } } /* * Save anything left as an argument. * Traditionally we have treated 'IFS=':'; set -- x$IFS' as * generating 2 arguments, the second of which is empty. * Some recent clarification of the Posix spec say that it * should only generate one.... */ if (had_param_ch || *start != 0) { VTRACE(DBG_EXPAND, (" T<%s>", start)); sp = stalloc(sizeof(*sp)); sp->text = start; *arglist->lastp = sp; arglist->lastp = &sp->next; } VTRACE(DBG_EXPAND, ("\n")); } STATIC void ifsfree(void) { while (ifsfirst.next != NULL) { struct ifsregion *ifsp; INTOFF; ifsp = ifsfirst.next->next; ckfree(ifsfirst.next); ifsfirst.next = ifsp; INTON; } ifslastp = NULL; ifsfirst.next = NULL; } /* * Expand shell metacharacters. At this point, the only control characters * should be escapes. The results are stored in the list exparg. */ char *expdir; STATIC void expandmeta(struct strlist *str, int flag) { char *p; struct strlist **savelastp; struct strlist *sp; char c; /* TODO - EXP_REDIR */ while (str) { p = str->text; for (;;) { /* fast check for meta chars */ if ((c = *p++) == '\0') goto nometa; if (c == '*' || c == '?' || c == '[' || c == '!') break; } savelastp = exparg.lastp; INTOFF; if (expdir == NULL) { int i = strlen(str->text); expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ } expmeta(expdir, str->text); ckfree(expdir); expdir = NULL; INTON; if (exparg.lastp == savelastp) { /* * no matches */ nometa: *exparg.lastp = str; rmescapes(str->text); exparg.lastp = &str->next; } else { *exparg.lastp = NULL; *savelastp = sp = expsort(*savelastp); while (sp->next != NULL) sp = sp->next; exparg.lastp = &sp->next; } str = str->next; } } STATIC void add_args(struct strlist *str) { while (str) { *exparg.lastp = str; rmescapes(str->text); exparg.lastp = &str->next; str = str->next; } } /* * Do metacharacter (i.e. *, ?, [...]) expansion. */ STATIC void expmeta(char *enddir, char *name) { char *p; const char *cp; char *q; char *start; char *endname; int metaflag; struct stat statb; DIR *dirp; struct dirent *dp; int atend; int matchdot; metaflag = 0; start = name; for (p = name ; ; p++) { if (*p == '*' || *p == '?') metaflag = 1; else if (*p == '[') { q = p + 1; if (*q == '!') q++; for (;;) { while (*q == CTLQUOTEMARK || *q == CTLNONL) q++; if (*q == CTLESC) q++; if (*q == '/' || *q == '\0') break; if (*++q == ']') { metaflag = 1; break; } } } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { metaflag = 1; } else if (*p == '\0') break; else if (*p == CTLQUOTEMARK || *p == CTLNONL) continue; else if (*p == CTLESC) p++; if (*p == '/') { if (metaflag) break; start = p + 1; } } if (metaflag == 0) { /* we've reached the end of the file name */ if (enddir != expdir) metaflag++; for (p = name ; ; p++) { if (*p == CTLQUOTEMARK || *p == CTLNONL) continue; if (*p == CTLESC) p++; *enddir++ = *p; if (*p == '\0') break; } if (metaflag == 0 || lstat(expdir, &statb) >= 0) addfname(expdir); return; } endname = p; if (start != name) { p = name; while (p < start) { while (*p == CTLQUOTEMARK || *p == CTLNONL) p++; if (*p == CTLESC) p++; *enddir++ = *p++; } } if (enddir == expdir) { cp = "."; } else if (enddir == expdir + 1 && *expdir == '/') { cp = "/"; } else { cp = expdir; enddir[-1] = '\0'; } if ((dirp = opendir(cp)) == NULL) return; if (enddir != expdir) enddir[-1] = '/'; if (*endname == 0) { atend = 1; } else { atend = 0; *endname++ = '\0'; } matchdot = 0; p = start; while (*p == CTLQUOTEMARK || *p == CTLNONL) p++; if (*p == CTLESC) p++; if (*p == '.') matchdot++; while (! int_pending() && (dp = readdir(dirp)) != NULL) { if (dp->d_name[0] == '.' && ! matchdot) continue; if (patmatch(start, dp->d_name, 0)) { if (atend) { scopy(dp->d_name, enddir); addfname(expdir); } else { for (p = enddir, cp = dp->d_name; (*p++ = *cp++) != '\0';) continue; p[-1] = '/'; expmeta(p, endname); } } } closedir(dirp); if (! atend) endname[-1] = '/'; } /* * Add a file name to the list. */ STATIC void addfname(char *name) { char *p; struct strlist *sp; p = stalloc(strlen(name) + 1); scopy(name, p); sp = stalloc(sizeof(*sp)); sp->text = p; *exparg.lastp = sp; exparg.lastp = &sp->next; } /* * Sort the results of file name expansion. It calculates the number of * strings to sort and then calls msort (short for merge sort) to do the * work. */ STATIC struct strlist * expsort(struct strlist *str) { int len; struct strlist *sp; len = 0; for (sp = str ; sp ; sp = sp->next) len++; return msort(str, len); } STATIC struct strlist * msort(struct strlist *list, int len) { struct strlist *p, *q = NULL; struct strlist **lpp; int half; int n; if (len <= 1) return list; half = len >> 1; p = list; for (n = half ; --n >= 0 ; ) { q = p; p = p->next; } q->next = NULL; /* terminate first half of list */ q = msort(list, half); /* sort first half of list */ p = msort(p, len - half); /* sort second half */ lpp = &list; for (;;) { if (strcmp(p->text, q->text) < 0) { *lpp = p; lpp = &p->next; if ((p = *lpp) == NULL) { *lpp = q; break; } } else { *lpp = q; lpp = &q->next; if ((q = *lpp) == NULL) { *lpp = p; break; } } } return list; } /* * See if a character matches a character class, starting at the first colon * of "[:class:]". * If a valid character class is recognized, a pointer to the next character * after the final closing bracket is stored into *end, otherwise a null * pointer is stored into *end. */ static int match_charclass(const char *p, wchar_t chr, const char **end) { char name[20]; char *nameend; wctype_t cclass; *end = NULL; p++; nameend = strstr(p, ":]"); if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) || nameend == p) return 0; memcpy(name, p, nameend - p); name[nameend - p] = '\0'; *end = nameend + 2; cclass = wctype(name); /* An unknown class matches nothing but is valid nevertheless. */ if (cclass == 0) return 0; return iswctype(chr, cclass); } /* * Returns true if the pattern matches the string. */ STATIC int patmatch(const char *pattern, const char *string, int squoted) { const char *p, *q, *end; const char *bt_p, *bt_q; char c; wchar_t wc, wc2; p = pattern; q = string; bt_p = NULL; bt_q = NULL; for (;;) { switch (c = *p++) { case '\0': if (*q != '\0') goto backtrack; return 1; case CTLESC: if (squoted && *q == CTLESC) q++; if (*q++ != *p++) goto backtrack; break; case CTLQUOTEMARK: case CTLNONL: continue; case '?': if (squoted && *q == CTLESC) q++; if (*q++ == '\0') return 0; break; case '*': c = *p; while (c == CTLQUOTEMARK || c == '*') c = *++p; if (c != CTLESC && c != CTLQUOTEMARK && c != CTLNONL && c != '?' && c != '*' && c != '[') { while (*q != c) { if (squoted && *q == CTLESC && q[1] == c) break; if (*q == '\0') return 0; if (squoted && *q == CTLESC) q++; q++; } } /* * First try the shortest match for the '*' that * could work. We can forget any earlier '*' since * there is no way having it match more characters * can help us, given that we are already here. */ bt_p = p; bt_q = q; break; case '[': { const char *savep, *saveq, *endp; int invert, found; unsigned char chr; endp = p; if (*endp == '!') endp++; for (;;) { while (*endp == CTLQUOTEMARK || *endp==CTLNONL) endp++; if (*endp == '\0') goto dft; /* no matching ] */ if (*endp == CTLESC) endp++; if (*++endp == ']') break; } invert = 0; savep = p, saveq = q; invert = 0; if (*p == '!' || *p == '^') { invert++; p++; } found = 0; if (*q == '\0') return 0; chr = (unsigned char)*q++; c = *p++; do { if (c == CTLQUOTEMARK || c == CTLNONL) continue; if (c == '\0') { p = savep, q = saveq; c = '['; goto dft; } if (c == '[' && *p == ':') { found |= match_charclass(p, chr, &end); if (end != NULL) p = end; } if (c == CTLESC) c = *p++; wc = (unsigned char)c; if (*p == '-' && p[1] != ']') { p++; if (*p == CTLESC) p++; wc2 = (unsigned char)*p++; if ( collate_range_cmp(chr, wc) >= 0 && collate_range_cmp(chr, wc2) <= 0 ) found = 1; } else { if (chr == wc) found = 1; } } while ((c = *p++) != ']'); if (found == invert) goto backtrack; break; } dft: default: if (squoted && *q == CTLESC) q++; if (*q++ == c) break; backtrack: /* * If we have a mismatch (other than hitting the end * of the string), go back to the last '*' seen and * have it match one additional character. */ if (bt_p == NULL) return 0; if (*bt_q == '\0') return 0; bt_q++; p = bt_p; q = bt_q; break; } } } /* * Remove any CTLESC or CTLNONL characters from a string. */ void rmescapes(char *str) { char *p, *q; p = str; while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLNONL) { if (*p++ == '\0') return; } q = p; while (*p) { if (*p == CTLQUOTEMARK || *p == CTLNONL) { p++; continue; } if (*p == CTLESC) p++; *q++ = *p++; } *q = '\0'; } /* * and a special version for dealing with expressions to be parsed * by the arithmetic evaluator. That needs to be able to count \n's * even ones that were \newline elided \n's, so we have to put the * latter back into the string - just being careful to put them only * at a place where white space can reasonably occur in the string * -- then the \n we insert will just be white space, and ignored * for all purposes except line counting. */ void rmescapes_nl(char *str) { char *p, *q; int nls = 0, holdnl = 0, holdlast; p = str; while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLNONL) { if (*p++ == '\0') return; } if (p > str) /* must reprocess char before stopper (if any) */ --p; /* so we do not place a \n badly */ q = p; while (*p) { if (*p == CTLQUOTEMARK) { p++; continue; } if (*p == CTLNONL) { p++; nls++; continue; } if (*p == CTLESC) p++; holdlast = holdnl; holdnl = is_in_name(*p); /* letters, digits, _ */ if (q == str || is_space(q[-1]) || (*p != '=' && q[-1] != *p)) { if (nls > 0 && holdnl != holdlast) { while (nls > 0) *q++ = '\n', nls--; } } *q++ = *p++; } while (--nls >= 0) *q++ = '\n'; *q = '\0'; } /* * See if a pattern matches in a case statement. */ int casematch(union node *pattern, char *val) { struct stackmark smark; int result; char *p; setstackmark(&smark); argbackq = pattern->narg.backquote; STARTSTACKSTR(expdest); ifslastp = NULL; argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); STPUTC('\0', expdest); p = grabstackstr(expdest); result = patmatch(p, val, 0); popstackmark(&smark); return result; } /* * Our own itoa(). Assumes result buffer is on the stack */ STATIC char * cvtnum(int num, char *buf) { char temp[32]; int neg = num < 0; char *p = temp + sizeof temp - 1; if (neg) num = -num; *p = '\0'; do { *--p = num % 10 + '0'; } while ((num /= 10) != 0 && p > temp + 1); if (neg) *--p = '-'; while (*p) STPUTC(*p++, buf); return buf; } /* * Do most of the work for wordexp(3). */ int wordexpcmd(int argc, char **argv) { size_t len; int i; out1fmt("%d", argc - 1); out1c('\0'); for (i = 1, len = 0; i < argc; i++) len += strlen(argv[i]); out1fmt("%zu", len); out1c('\0'); for (i = 1; i < argc; i++) { out1str(argv[i]); out1c('\0'); } return (0); }