/* Check if coded string s is a variable name */ int is_wdvarname(const char *s, bool aok) { const char *p = skip_wdvarname(s, aok); return (p != s && p[0] == EOS); }
/* Check if coded string s is a variable assignment */ int is_wdvarassign(const char *s) { const char *p = skip_wdvarname(s, true); return (p != s && p[0] == CHAR && (p[1] == '=' || (p[1] == '+' && p[2] == CHAR && p[3] == '='))); }
/* * 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); }
/* * print a command tree */ static void ptree(struct op *t, int indent, struct shf *shf) { const char **w; struct ioword **ioact; struct op *t1; int i; const char *ccp; Chain: if (t == NULL) return; switch (t->type) { case TCOM: prevent_semicolon = false; /* special-case 'var=<<EOF' (cf. exec.c:execute) */ if (t->args && /* we have zero arguments, i.e. no program 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]->ioflag & 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) || /* or "varname+=" */ (ccp[1] == '+' && ccp[2] == CHAR && ccp[3] == '=' && ccp[4] == EOS))) { fptreef(shf, indent, Tf_S, t->vars[0]); break; } if (t->vars) { w = (const char **)t->vars; while (*w) fptreef(shf, indent, Tf_S_, *w++); } else shf_puts("#no-vars# ", shf); if (t->args) { w = t->args; if (*w && **w == CHAR) { char *cp = wdstrip(*w++, WDS_TPUTS); if (valid_alias_name(cp)) shf_putc('\\', shf); shf_puts(cp, shf); shf_putc(' ', shf); afree(cp, ATEMP); } while (*w) fptreef(shf, indent, Tf_S_, *w++); } else shf_puts("#no-args# ", shf); break; case TEXEC: t = t->left; goto Chain; case TPAREN: fptreef(shf, indent + 2, "( %T) ", t->left); break; case TPIPE: fptreef(shf, indent, "%T| ", t->left); t = t->right; goto Chain; case TLIST: fptreef(shf, indent, "%T%;", t->left); t = t->right; goto Chain; case TOR: case TAND: fptreef(shf, indent, "%T%s %T", t->left, (t->type == TOR) ? "||" : "&&", t->right); break; case TBANG: shf_puts("! ", shf); prevent_semicolon = false; t = t->right; goto Chain; case TDBRACKET: w = t->args; shf_puts("[[", shf); while (*w) fptreef(shf, indent, Tf__S, *w++); shf_puts(" ]] ", shf); break; case TSELECT: case TFOR: fptreef(shf, indent, "%s %s ", (t->type == TFOR) ? "for" : Tselect, t->str); if (t->vars != NULL) { shf_puts("in ", shf); w = (const char **)t->vars; while (*w) fptreef(shf, indent, Tf_S_, *w++); fptreef(shf, indent, Tft_end); } fptreef(shf, indent + INDENT, "do%N%T", t->left); fptreef(shf, indent, "%;done "); break; case TCASE: fptreef(shf, indent, "case %S in", t->str); for (t1 = t->left; t1 != NULL; t1 = t1->right) { fptreef(shf, indent, "%N("); w = (const char **)t1->vars; while (*w) { fptreef(shf, indent, "%S%c", *w, (w[1] != NULL) ? '|' : ')'); ++w; } fptreef(shf, indent + INDENT, "%N%T%N;%c", t1->left, t1->u.charflag); } fptreef(shf, indent, "%Nesac "); break; case TELIF: internal_errorf(TELIF_unexpected); /* FALLTHROUGH */ case TIF: i = 2; t1 = t; goto process_TIF; do { t1 = t1->right; i = 0; fptreef(shf, indent, Tft_end); process_TIF: /* 5 == strlen("elif ") */ fptreef(shf, indent + 5 - i, Telif_pT + i, t1->left); t1 = t1->right; if (t1->left != NULL) { fptreef(shf, indent, Tft_end); fptreef(shf, indent + INDENT, "%s%N%T", "then", t1->left); } } while (t1->right && t1->right->type == TELIF); if (t1->right != NULL) { fptreef(shf, indent, Tft_end); fptreef(shf, indent + INDENT, "%s%N%T", "else", t1->right); } fptreef(shf, indent, "%;fi "); break; case TWHILE: case TUNTIL: /* 6 == strlen("while "/"until ") */ fptreef(shf, indent + 6, Tf_s_T, (t->type == TWHILE) ? "while" : "until", t->left); fptreef(shf, indent, Tft_end); fptreef(shf, indent + INDENT, "do%N%T", t->right); fptreef(shf, indent, "%;done "); break; case TBRACE: fptreef(shf, indent + INDENT, "{%N%T", t->left); fptreef(shf, indent, "%;} "); break; case TCOPROC: fptreef(shf, indent, "%T|& ", t->left); prevent_semicolon = true; break; case TASYNC: fptreef(shf, indent, "%T& ", t->left); prevent_semicolon = true; break; case TFUNCT: fpFUNCTf(shf, indent, tobool(t->u.ksh_func), t->str, t->left); break; case TTIME: fptreef(shf, indent, Tf_s_T, Ttime, t->left); break; default: shf_puts("<botch>", shf); prevent_semicolon = false; break; } if ((ioact = t->ioact) != NULL) { bool need_nl = false; while (*ioact != NULL) pioact(shf, *ioact++); /* Print here documents after everything else... */ ioact = t->ioact; while (*ioact != NULL) { struct ioword *iop = *ioact++; /* heredoc is NULL when tracing (set -x) */ if ((iop->ioflag & (IOTYPE | IOHERESTR)) == IOHERE && iop->heredoc) { shf_putc('\n', shf); shf_puts(iop->heredoc, shf); fptreef(shf, indent, Tf_s, evalstr(iop->delim, 0)); need_nl = true; } } /* * Last delimiter must be followed by a newline (this * often leads to an extra blank line, but it's not * worth worrying about) */ if (need_nl) { shf_putc('\n', shf); prevent_semicolon = true; } } }