void yyerror(const char *fmt, ...) { va_list va; /* pop aliases and re-reads */ while (source->type == SALIAS || source->type == SREREAD) source = source->next; /* zap pending input */ source->str = null; error_prefix(true); va_start(va, fmt); shf_vfprintf(shl_out, fmt, va); va_end(va); errorfz(); }
/* * execute command tree */ int execute(struct op * volatile t, /* if XEXEC don't fork */ volatile int flags, volatile int * volatile xerrok) { int i; volatile int rv = 0, dummy = 0; int pv[2]; const char ** volatile ap = NULL; char ** volatile up; const char *s, *ccp; struct ioword **iowp; struct tbl *tp = NULL; char *cp; if (t == NULL) return (0); /* Caller doesn't care if XERROK should propagate. */ if (xerrok == NULL) xerrok = &dummy; if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE) /* run in sub-process */ return (exchild(t, flags & ~XTIME, xerrok, -1)); newenv(E_EXEC); if (trap) runtraps(0); /* we want to run an executable, do some variance checks */ if (t->type == TCOM) { /* check if this is 'var=<<EOF' */ if ( /* we have zero arguments, i.e. no programme to run */ t->args[0] == NULL && /* we have exactly one variable assignment */ t->vars[0] != NULL && t->vars[1] == NULL && /* we have exactly one I/O redirection */ t->ioact != NULL && t->ioact[0] != NULL && t->ioact[1] == NULL && /* of type "here document" (or "here string") */ (t->ioact[0]->flag & IOTYPE) == IOHERE && /* the variable assignment begins with a valid varname */ (ccp = skip_wdvarname(t->vars[0], true)) != t->vars[0] && /* and has no right-hand side (i.e. "varname=") */ ccp[0] == CHAR && ccp[1] == '=' && ccp[2] == EOS && /* plus we can have a here document content */ herein(t->ioact[0], &cp) == 0 && cp && *cp) { char *sp = cp, *dp; size_t n = ccp - t->vars[0] + 2, z; /* drop redirection (will be garbage collected) */ t->ioact = NULL; /* set variable to its expanded value */ z = strlen(cp) + 1; if (notoktomul(z, 2) || notoktoadd(z * 2, n)) internal_errorf(Toomem, (unsigned long)-1); dp = alloc(z * 2 + n, ATEMP); memcpy(dp, t->vars[0], n); t->vars[0] = dp; dp += n; while (*sp) { *dp++ = QCHAR; *dp++ = *sp++; } *dp = EOS; /* free the expanded value */ afree(cp, APERM); } /* * Clear subst_exstat before argument expansion. Used by * null commands (see comexec() and c_eval()) and by c_set(). */ subst_exstat = 0; /* for $LINENO */ current_lineno = t->lineno; /* * POSIX says expand command words first, then redirections, * and assignments last.. */ up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE); if (flags & XTIME) /* Allow option parsing (bizarre, but POSIX) */ timex_hook(t, &up); ap = (const char **)up; if (Flag(FXTRACE) && ap[0]) { shf_puts(substitute(str_val(global("PS4")), 0), shl_out); for (i = 0; ap[i]; i++) shf_fprintf(shl_out, "%s%c", ap[i], ap[i + 1] ? ' ' : '\n'); shf_flush(shl_out); } if (ap[0]) tp = findcom(ap[0], FC_BI|FC_FUNC); } flags &= ~XTIME; if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) { e->savefd = alloc2(NUFILE, sizeof(short), ATEMP); /* initialise to not redirected */ memset(e->savefd, 0, NUFILE * sizeof(short)); } /* mark for replacement later (unless TPIPE) */ vp_pipest->flag |= INT_L; /* do redirection, to be restored in quitenv() */ if (t->ioact != NULL) for (iowp = t->ioact; *iowp != NULL; iowp++) { if (iosetup(*iowp, tp) < 0) { exstat = rv = 1; /* * Redirection failures for special commands * cause (non-interactive) shell to exit. */ if (tp && tp->type == CSHELL && (tp->flag & SPEC_BI)) errorfz(); /* Deal with FERREXIT, quitenv(), etc. */ goto Break; } } switch (t->type) { case TCOM: rv = comexec(t, tp, (const char **)ap, flags, xerrok); break; case TPAREN: rv = execute(t->left, flags | XFORK, xerrok); break; case TPIPE: flags |= XFORK; flags &= ~XEXEC; e->savefd[0] = savefd(0); e->savefd[1] = savefd(1); while (t->type == TPIPE) { openpipe(pv); /* stdout of curr */ ksh_dup2(pv[1], 1, false); /** * Let exchild() close pv[0] in child * (if this isn't done, commands like * (: ; cat /etc/termcap) | sleep 1 * will hang forever). */ exchild(t->left, flags | XPIPEO | XCCLOSE, NULL, pv[0]); /* stdin of next */ ksh_dup2(pv[0], 0, false); closepipe(pv); flags |= XPIPEI; t = t->right; } /* stdout of last */ restfd(1, e->savefd[1]); /* no need to re-restore this */ e->savefd[1] = 0; /* Let exchild() close 0 in parent, after fork, before wait */ i = exchild(t, flags | XPCLOSE | XPIPEST, xerrok, 0); if (!(flags&XBGND) && !(flags&XXCOM)) rv = i; break; case TLIST: while (t->type == TLIST) { execute(t->left, flags & XERROK, NULL); t = t->right; } rv = execute(t, flags & XERROK, xerrok); break; case TCOPROC: { #ifndef MKSH_NOPROSPECTOFWORK sigset_t omask; /* * Block sigchild as we are using things changed in the * signal handler */ sigprocmask(SIG_BLOCK, &sm_sigchld, &omask); e->type = E_ERRH; if ((i = kshsetjmp(e->jbuf))) { sigprocmask(SIG_SETMASK, &omask, NULL); quitenv(NULL); unwind(i); /* NOTREACHED */ } #endif /* Already have a (live) co-process? */ if (coproc.job && coproc.write >= 0) errorf("coprocess already exists"); /* Can we re-use the existing co-process pipe? */ coproc_cleanup(true); /* do this before opening pipes, in case these fail */ e->savefd[0] = savefd(0); e->savefd[1] = savefd(1); openpipe(pv); if (pv[0] != 0) { ksh_dup2(pv[0], 0, false); close(pv[0]); } coproc.write = pv[1]; coproc.job = NULL; if (coproc.readw >= 0) ksh_dup2(coproc.readw, 1, false); else { openpipe(pv); coproc.read = pv[0]; ksh_dup2(pv[1], 1, false); /* closed before first read */ coproc.readw = pv[1]; coproc.njobs = 0; /* create new coprocess id */ ++coproc.id; } #ifndef MKSH_NOPROSPECTOFWORK sigprocmask(SIG_SETMASK, &omask, NULL); /* no more need for error handler */ e->type = E_EXEC; #endif /* * exchild() closes coproc.* in child after fork, * will also increment coproc.njobs when the * job is actually created. */ flags &= ~XEXEC; exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE, NULL, coproc.readw); break; } case TASYNC: /* * XXX non-optimal, I think - "(foo &)", forks for (), * forks again for async... parent should optimise * this to "foo &"... */ rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok); break; case TOR: case TAND: rv = execute(t->left, XERROK, xerrok); if ((rv == 0) == (t->type == TAND)) rv = execute(t->right, XERROK, xerrok); flags |= XERROK; if (xerrok) *xerrok = 1; break; case TBANG: rv = !execute(t->right, XERROK, xerrok); flags |= XERROK; if (xerrok) *xerrok = 1; break; case TDBRACKET: { Test_env te; te.flags = TEF_DBRACKET; te.pos.wp = t->args; te.isa = dbteste_isa; te.getopnd = dbteste_getopnd; te.eval = test_eval; te.error = dbteste_error; rv = test_parse(&te); break; } case TFOR: case TSELECT: { volatile bool is_first = true; ap = (t->vars == NULL) ? e->loc->argv + 1 : (const char **)eval((const char **)t->vars, DOBLANK | DOGLOB | DOTILDE); e->type = E_LOOP; while ((i = kshsetjmp(e->jbuf))) { if ((e->flags&EF_BRKCONT_PASS) || (i != LBREAK && i != LCONTIN)) { quitenv(NULL); unwind(i); } else if (i == LBREAK) { rv = 0; goto Break; } } /* in case of a continue */ rv = 0; if (t->type == TFOR) { while (*ap != NULL) { setstr(global(t->str), *ap++, KSH_UNWIND_ERROR); rv = execute(t->left, flags & XERROK, xerrok); } } else { /* TSELECT */ for (;;) { if (!(ccp = do_selectargs(ap, is_first))) { rv = 1; break; } is_first = false; setstr(global(t->str), ccp, KSH_UNWIND_ERROR); execute(t->left, flags & XERROK, xerrok); } } break; } case TWHILE: case TUNTIL: e->type = E_LOOP; while ((i = kshsetjmp(e->jbuf))) { if ((e->flags&EF_BRKCONT_PASS) || (i != LBREAK && i != LCONTIN)) { quitenv(NULL); unwind(i); } else if (i == LBREAK) { rv = 0; goto Break; } } /* in case of a continue */ rv = 0; while ((execute(t->left, XERROK, NULL) == 0) == (t->type == TWHILE)) rv = execute(t->right, flags & XERROK, xerrok); break; case TIF: case TELIF: if (t->right == NULL) /* should be error */ break; rv = execute(t->left, XERROK, NULL) == 0 ? execute(t->right->left, flags & XERROK, xerrok) : execute(t->right->right, flags & XERROK, xerrok); break; case TCASE: i = 0; ccp = evalstr(t->str, DOTILDE); for (t = t->left; t != NULL && t->type == TPAT; t = t->right) { for (ap = (const char **)t->vars; *ap; ap++) { if (i || ((s = evalstr(*ap, DOTILDE|DOPAT)) && gmatchx(ccp, s, false))) { rv = execute(t->left, flags & XERROK, xerrok); i = 0; switch (t->u.charflag) { case '&': i = 1; /* FALLTHROUGH */ case '|': goto TCASE_next; } goto TCASE_out; } } i = 0; TCASE_next: /* empty */; } TCASE_out: break; case TBRACE: rv = execute(t->left, flags & XERROK, xerrok); break; case TFUNCT: rv = define(t->str, t); break; case TTIME: /* * Clear XEXEC so nested execute() call doesn't exit * (allows "ls -l | time grep foo"). */ rv = timex(t, flags & ~XEXEC, xerrok); break; case TEXEC: /* an eval'd TCOM */ s = t->args[0]; up = makenv(); restoresigs(); cleanup_proc_env(); { union mksh_ccphack cargs; cargs.ro = t->args; execve(t->str, cargs.rw, up); rv = errno; } if (rv == ENOEXEC) scriptexec(t, (const char **)up); else errorf("%s: %s", s, cstrerror(rv)); } Break: exstat = rv & 0xFF; if (vp_pipest->flag & INT_L) { unset(vp_pipest, 1); vp_pipest->flag = DEFINED | ISSET | INTEGER | RDONLY | ARRAY | INT_U; vp_pipest->val.i = rv; } /* restores IO */ quitenv(NULL); if ((flags&XEXEC)) /* exit child */ unwind(LEXIT); if (rv != 0 && !(flags & XERROK) && (xerrok == NULL || !*xerrok)) { if (Flag(FERREXIT) & 0x80) { /* inside eval */ Flag(FERREXIT) = 0; } else { trapsig(ksh_SIGERR); if (Flag(FERREXIT)) unwind(LERROR); } } return (rv); }
/* * lookup variable (according to (set&LOCAL)), set its attributes * (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL, LCASEV, * UCASEV_AL), and optionally set its value if an assignment. */ struct tbl * typeset(const char *var, uint32_t set, uint32_t clr, int field, int base) { struct tbl *vp; struct tbl *vpbase, *t; char *tvar; const char *val; size_t len; bool vappend = false; enum namerefflag new_refflag = SRF_NOP; if ((set & (ARRAY | ASSOC)) == ASSOC) { new_refflag = SRF_ENABLE; set &= ~(ARRAY | ASSOC); } if ((clr & (ARRAY | ASSOC)) == ASSOC) { new_refflag = SRF_DISABLE; clr &= ~(ARRAY | ASSOC); } /* check for valid variable name, search for value */ val = skip_varname(var, false); if (val == var) { /* no variable name given */ return (NULL); } if (*val == '[') { if (new_refflag != SRF_NOP) errorf("%s: %s", var, "reference variable can't be an array"); len = array_ref_len(val); if (len == 0) return (NULL); /* * IMPORT is only used when the shell starts up and is * setting up its environment. Allow only simple array * references at this time since parameter/command * substitution is performed on the [expression] which * would be a major security hole. */ if (set & IMPORT) { size_t i; for (i = 1; i < len - 1; i++) if (!ksh_isdigit(val[i])) return (NULL); } val += len; } if (val[0] == '=') { strndupx(tvar, var, val - var, ATEMP); ++val; } else if (set & IMPORT) { /* environment invalid variable name or no assignment */ return (NULL); } else if (val[0] == '+' && val[1] == '=') { strndupx(tvar, var, val - var, ATEMP); val += 2; vappend = true; } else if (val[0] != '\0') { /* other invalid variable names (not from environment) */ return (NULL); } else { /* just varname with no value part nor equals sign */ strdupx(tvar, var, ATEMP); val = NULL; /* handle foo[*] => foo (whole array) mapping for R39b */ len = strlen(tvar); if (len > 3 && tvar[len - 3] == '[' && tvar[len - 2] == '*' && tvar[len - 1] == ']') tvar[len - 3] = '\0'; } if (new_refflag == SRF_ENABLE) { const char *qval, *ccp; /* bail out on 'nameref foo+=bar' */ if (vappend) errorf("appending not allowed for nameref"); /* find value if variable already exists */ if ((qval = val) == NULL) { varsearch(e->loc, &vp, tvar, hash(tvar)); if (vp == NULL) goto nameref_empty; qval = str_val(vp); } /* check target value for being a valid variable name */ ccp = skip_varname(qval, false); if (ccp == qval) { if (ksh_isdigit(qval[0])) { int c; if (getn(qval, &c)) goto nameref_rhs_checked; } else if (qval[1] == '\0') switch (qval[0]) { case '$': case '!': case '?': case '#': case '-': goto nameref_rhs_checked; } nameref_empty: errorf("%s: %s", var, "empty nameref target"); } len = (*ccp == '[') ? array_ref_len(ccp) : 0; if (ccp[len]) { /* * works for cases "no array", "valid array with * junk after it" and "invalid array"; in the * latter case, len is also 0 and points to '[' */ errorf("%s: %s", qval, "nameref target not a valid parameter name"); } nameref_rhs_checked: /* prevent nameref loops */ while (qval) { if (!strcmp(qval, tvar)) errorf("%s: %s", qval, "expression recurses on parameter"); varsearch(e->loc, &vp, qval, hash(qval)); qval = NULL; if (vp && ((vp->flag & (ARRAY | ASSOC)) == ASSOC)) qval = str_val(vp); } } /* prevent typeset from creating a local PATH/ENV/SHELL */ if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 || strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0)) errorf("%s: %s", tvar, "restricted"); innermost_refflag = new_refflag; vp = (set & LOCAL) ? local(tvar, tobool(set & LOCAL_COPY)) : global(tvar); if (new_refflag == SRF_DISABLE && (vp->flag & (ARRAY|ASSOC)) == ASSOC) vp->flag &= ~ASSOC; else if (new_refflag == SRF_ENABLE) { if (vp->flag & ARRAY) { struct tbl *a, *tmp; /* free up entire array */ for (a = vp->u.array; a; ) { tmp = a; a = a->u.array; if (tmp->flag & ALLOC) afree(tmp->val.s, tmp->areap); afree(tmp, tmp->areap); } vp->u.array = NULL; vp->flag &= ~ARRAY; } vp->flag |= ASSOC; } set &= ~(LOCAL|LOCAL_COPY); vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp; /* * only allow export flag to be set; AT&T ksh allows any * attribute to be changed which means it can be truncated or * modified (-L/-R/-Z/-i) */ if ((vpbase->flag & RDONLY) && (val || clr || (set & ~EXPORT))) /* XXX check calls - is error here ok by POSIX? */ errorfx(2, "read-only: %s", tvar); afree(tvar, ATEMP); /* most calls are with set/clr == 0 */ if (set | clr) { bool ok = true; /* * XXX if x[0] isn't set, there will be problems: need * to have one copy of attributes for arrays... */ for (t = vpbase; t; t = t->u.array) { bool fake_assign; char *s = NULL; char *free_me = NULL; fake_assign = (t->flag & ISSET) && (!val || t != vp) && ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) || ((t->flag & INTEGER) && (clr & INTEGER)) || (!(t->flag & INTEGER) && (set & INTEGER))); if (fake_assign) { if (t->flag & INTEGER) { s = str_val(t); free_me = NULL; } else { s = t->val.s + t->type; free_me = (t->flag & ALLOC) ? t->val.s : NULL; } t->flag &= ~ALLOC; } if (!(t->flag & INTEGER) && (set & INTEGER)) { t->type = 0; t->flag &= ~ALLOC; } t->flag = (t->flag | set) & ~clr; /* * Don't change base if assignment is to be * done, in case assignment fails. */ if ((set & INTEGER) && base > 0 && (!val || t != vp)) t->type = base; if (set & (LJUST|RJUST|ZEROFIL)) t->u2.field = field; if (fake_assign) { if (!setstr(t, s, KSH_RETURN_ERROR)) { /* * Somewhat arbitrary action * here: zap contents of * variable, but keep the flag * settings. */ ok = false; if (t->flag & INTEGER) t->flag &= ~ISSET; else { if (t->flag & ALLOC) afree(t->val.s, t->areap); t->flag &= ~(ISSET|ALLOC); t->type = 0; } } if (free_me) afree(free_me, t->areap); } } if (!ok) errorfz(); } if (val != NULL) { char *tval; if (vappend) { tval = shf_smprintf("%s%s", str_val(vp), val); val = tval; } else tval = NULL; if (vp->flag&INTEGER) { /* do not zero base before assignment */ setstr(vp, val, KSH_UNWIND_ERROR | 0x4); /* done after assignment to override default */ if (base > 0) vp->type = base; } else /* setstr can't fail (readonly check already done) */ setstr(vp, val, KSH_RETURN_ERROR | 0x4); if (tval != NULL) afree(tval, ATEMP); } /* only x[0] is ever exported, so use vpbase */ if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) && vpbase->type == 0) exportprep(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null); return (vp); }