/* sh.c - toybox shell
*
* Copyright 2006 Rob Landley <rob@landley.net>
*
* The POSIX-2008/SUSv4 spec for this is at:
* http://opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
* and http://opengroup.org/onlinepubs/9699919799/utilities/sh.html
*
* The first link describes the following shell builtins:
*
* break colon continue dot eval exec exit export readonly return set shift
* times trap unset
*
* The second link (the utilities directory) also contains specs for the
* following shell builtins:
*
* alias bg cd command fc fg getopts hash jobs kill read type ulimit
* umask unalias wait
*
* Things like the bash man page are good to read too.
*
* TODO: test that $PS1 color changes work without stupid \[ \] hack
* TODO: make fake pty wrapper for test infrastructure
* TODO: // Handle embedded NUL bytes in the command line.
* existing but considered builtins: false kill pwd true time
* buitins: alias bg command fc fg getopts jobs newgrp read umask unalias wait
* "special" builtins: break continue : . eval exec export readonly return set
* shift times trap unset
* | & ; < > ( ) $ ` \ " ' <space> <tab> <newline>
* * ? [ # ~ = %
* ! { } case do done elif else esac fi for if in then until while
* [[ ]] function select
* $@ $* $# $? $- $$ $! $0
* ENV HOME IFS LANG LC_ALL LINENO PATH PPID PS1 PS2 PS4 PWD
* label:
* TODO: test exit from "trap EXIT" doesn't recurse
* TODO: ! history expansion
* TODO: getuid() vs geteuid()
*
* bash man page:
* control operators || & && ; ;; ;& ;;& ( ) | |& <newline>
* reserved words
* ! case coproc do done elif else esac fi for function if in select
* then until while { } time [[ ]]
USE_SH(NEWTOY(cd, ">1LP[-LP]", TOYFLAG_NOFORK))
USE_SH(NEWTOY(exit, NULL, TOYFLAG_NOFORK))
USE_SH(NEWTOY(sh, "(noediting)(noprofile)(norc)sc:i", TOYFLAG_BIN))
USE_SH(OLDTOY(toysh, sh, TOYFLAG_BIN))
USE_SH(OLDTOY(bash, sh, TOYFLAG_BIN))
// Login lies in argv[0], so add some aliases to catch that
USE_SH(OLDTOY(-sh, sh, 0))
USE_SH(OLDTOY(-toysh, sh, 0))
USE_SH(OLDTOY(-bash, sh, 0))
config SH
bool "sh (toysh)"
default n
help
usage: sh [-c command] [script]
Command shell. Runs a shell script, or reads input interactively
and responds to it.
-c command line to execute
-i interactive mode (default when STDIN is a tty)
# These are here for the help text, they're not selectable and control nothing
config CD
bool
default n
depends on SH
help
usage: cd [-PL] [path]
Change current directory. With no arguments, go $HOME.
-P Physical path: resolve symlinks in path
-L Local path: .. trims directories off $PWD (default)
config EXIT
bool
default n
depends on SH
help
usage: exit [status]
Exit shell. If no return value supplied on command line, use value
of most recent command, or 0 if none.
*/
#define FOR_sh
#include "toys.h"
GLOBALS(
char *command;
long lineno;
char **locals, *subshell_env;
struct double_list functions;
unsigned options, jobcnt;
int hfd; // next high filehandle (>= 10)
// Running jobs.
struct sh_job {
struct sh_job *next, *prev;
unsigned jobno;
// Every pipeline has at least one set of arguments or it's Not A Thing
struct sh_arg {
char **v;
int c;
} pipeline;
// null terminated array of running processes in pipeline
struct sh_process {
struct sh_process *next, *prev;
struct arg_list *delete; // expanded strings
int *urd, envlen, pid, exit; // undo redirects, child PID, exit status
struct sh_arg arg;
} *procs, *proc;
} *jobs, *job;
)
#define BUGBUG 0
// ordered for greedy matching, so >&; becomes >& ; not > &;
// making these const means I need to typecast the const away later to
// avoid endless warnings.
static const char *redirectors[] = {"<<<", "<<-", "<<", "<&", "<>", "<", ">>",
">&", ">|", ">", "&>>", "&>", 0};
#define SH_NOCLOBBER 1 // set -C
// like error_msg() but exit from shell scripts
static void syntax_err(char *msg, ...)
{
va_list va;
va_start(va, msg);
verror_msg(msg, 0, va);
va_end(va);
if (*toys.optargs) xexit();
}
void array_add(char ***list, unsigned count, char *data)
{
if (!(count&31)) *list = xrealloc(*list, sizeof(char *)*(count+33));
(*list)[count] = data;
(*list)[count+1] = 0;
}
// TODO local variables
// Return index of variable within this list
static unsigned findvar(char **list, char *name, int len)
{
unsigned i;
for (i = 0; list[i]; i++)
if (!strncmp(list[i], name, len) && list[i][len] == '=') break;
return i;
}
// Assign one variable
// s: key=val
// type: 0 = whatever it was before, local otherwise
#define TAKE_MEM 0x80000000
// declare -aAilnrux
// ft
static void setvar(char *s, unsigned type)
{
unsigned uu;
int len = stridx(s, '=');
if (len == -1) {
error_msg("no = in setvar %s\n", s);
return;
}
if (type&TAKE_MEM) type ^= TAKE_MEM;
else s = xstrdup(s);
// local, export, readonly, integer...
// exported variable?
if (environ && environ[uu = findvar(environ, s, len)]) {
if (uu>=toys.envc) free(environ[uu]);
environ[uu] = s;
} else {
uu = 0;
if (TT.locals && TT.locals[uu = findvar(TT.locals, s, len)]) {
free(TT.locals[uu]);
TT.locals[uu] = s;
} else array_add(&TT.locals, uu, s);
}
}
// get variable of length len starting at s.
static char *getvarlen(char *s, int len)
{
int i;
if (TT.locals && TT.locals[i = findvar(TT.locals, s, len)])
return TT.locals[i]+len+1;
if (environ && environ[i = findvar(environ, s, len)])
return environ[i]+len+1;
return 0;
}
static char *getvar(char *s)
{
return getvarlen(s, strlen(s));
}
// returns pointer to next unquoted (or double quoted if dquot) char.
// handle \ '' "" `` $()
int skip_quote(char *s, int dquot, int *depth)
{
int i, q = dquot ? *depth : 0;
// quotes were checked for balance and overflow by parse_word()
for (i = 0; s[i]; i++) {
char c = s[i], qq = q ? toybuf[q-1] : 0;
if (c == '\\') i++;
else if (qq!='\'' && c=='$' && s[1]=='(') {
toybuf[q++] = ')';
i++;
} else if (q && qq==c) q--;
else if ((!q || qq==')') && (c=='"' || c=='\'' || c=='`')) toybuf[q++] = c;
else if (!q || (dquot && q==1 && qq=='"')) break;
}
if (dquot) *depth = q;
return i;
}
// add argument to an arg_list
void add_arg(struct arg_list **list, char *arg)
{
struct arg_list *al;
if (!list) return;
al = xmalloc(sizeof(struct arg_list));
al->next = *list;
al->arg = arg;
*list = al;
}
// quote removal, brace, tilde, parameter/variable, $(command),
// $((arithmetic)), split, path
#define NO_PATH (1<<0)
#define NO_SPLIT (1<<1)
#define NO_BRACE (1<<2)
#define NO_TILDE (1<<3)
#define NO_QUOTE (1<<4)
#define FORCE_COPY (1<<31)
#define FORCE_KEEP (1<<30)
// TODO: ${name:?error} causes an error/abort here (syntax_err longjmp?)
// TODO: $1 $@ $* need args marshalled down here: function+structure?
// arg = append to this
// new = string to expand
// flags = type of expansions (not) to do
// delete = append new allocations to this so they can be freed later
// TODO: at_args: $1 $2 $3 $* $@
static void expand_arg_nobrace(struct sh_arg *arg, char *old, unsigned flags,
struct arg_list **delete)
{
char *new = old;
if (flags&FORCE_KEEP) old = 0;
// TODO ls -l /proc/$$/fd
// Tilde expansion
if (!(flags&NO_TILDE) && *new == '~') {
struct passwd *pw = 0;
char *s, *ss, *sss;
// first expansion so don't need to free previous new
ss = 0;
for (s = new; *s && *s!=':' && *s!='/'; s++);
if (s-new==1) {
if (!(ss = getvar("HOME")) || !*ss) pw = bufgetpwuid(getuid());
} else {
// TODO bufgetpwnam
pw = getpwnam(sss = xstrndup(new+1, (s-new)-1));
free(sss);
}
if (pw && pw->pw_dir) ss = pw->pw_dir;
if (!ss || !*ss) ss = "/";
s = xmprintf("%s%s", ss, s);
if (old != new) free(new);
new = s;
}
// ${ $(( $( $[ $' ` " '
/*
while (*s) {
if (!quote && !(flags&NO_BRACE) && *s == '{') {
TODO this recurses
} else if (quote != '*s == '$') {
// *@#?-$!_0 "Special Paremeters" ($0 not affected by shift)
// 0-9 positional parameters
if (s[1] == '$'
// EUID GROUPS HOSTNAME HOSTTYPE=$(uname -m) MACHTYPE=$HOSTTYPE-unknown-linux
// OLDPWD OSTYPE=linux/android PIPESTATUS PPID PWD RANDOM REPLY SECONDS UID
// COLUMNS LINES HOME SHELL
// IFS PATH
// PS0 PS1='$ ' PS2='> ' PS3
}
}
// replacement
while (*s) {
if (*s == '$') {
s++;
} else if (*strchr("*?[{", *s)) {
s++;
} else if (*s == '<' || *s == '>') {
s++;
} else s++;
}
*/
// quote removal
if (!(flags&NO_QUOTE)) {
int to = 0, from = 0;
for (;;) {
char c = new[from++];
if (c == '"' || c=='\'') continue;
if (c == '\\' && new[from]) c = new[from++];
if (from != to && old == new) new = xstrdup(new);
if (!(new[to++] = c)) break;
}
}
// Record result.
if (old==new && (flags&FORCE_COPY)) new = xstrdup(new);
if (old!=new) add_arg(delete, new);
array_add(&arg->v, arg->c++, new);
}
// expand braces (ala {a,b,c}) and call expand_arg_nobrace() each permutation
static void expand_arg(struct sh_arg *arg, char *old, unsigned flags,
struct arg_list **delete)
{
struct brace {
struct brace *next, *prev, *stack;
int active, cnt, idx, commas[];
} *bb = 0, *blist = 0, *bstk, *bnext;
int i, j;
char *s, *ss;
// collect brace spans
if (!(flags&NO_BRACE)) for (i = 0; ; i++) {
i += skip_quote(old+i, 0, 0);
if (!bb && !old[i]) break;
if (bb && (!old[i] || old[i] == '}')) {
bb->active = bb->commas[bb->cnt+1] = i;
for (bnext = bb; bb && bb->active; bb = (bb==blist)?0:bb->prev);
if (!old[i] || !bnext->cnt) // discard commaless brace from start/middle
free(dlist_pop((blist == bnext) ? &blist : &bnext));
} else if (old[i] == '{') {
dlist_add_nomalloc((void *)&blist,
(void *)(bb = xzalloc(sizeof(struct brace)+34*4)));
bb->commas[0] = i;
} else if (!bb) continue;
else if (bb && old[i] == ',') {
if (bb->cnt && !(bb->cnt&31)) {
dlist_lpop(&blist);
dlist_add_nomalloc((void *)&blist,
(void *)(bb = xrealloc(bb, sizeof(struct brace)+(bb->cnt+34)*4)));
}
bb->commas[++bb->cnt] = i;
}
}
// TODO NOSPLIT with braces? (Collate with spaces?)
// If none, pass on verbatim
if (!blist) return expand_arg_nobrace(arg, old, flags, delete);
// enclose entire range in top level brace.
(bstk = xzalloc(sizeof(struct brace)+8))->commas[1] = strlen(old)+1;
bstk->commas[0] = -1;
// loop through each combination
for (;;) {
// Brace expansion can't be longer than original string. Keep start to {
s = ss = xmalloc(bstk->commas[1]);
// Append output from active braces (in "saved" list)
for (bb = blist; bb;) {
// keep prefix and push self onto stack
if (bstk == bb) bstk = bstk->stack; // pop self
i = bstk->commas[bstk->idx]+1;
if (bstk->commas[bstk->cnt+1]>bb->commas[0])
s = stpncpy(s, old+i, bb->commas[0]-i);
// pop sibling
if (bstk->commas[bstk->cnt+1]<bb->commas[0]) bstk = bstk->stack;
bb->stack = bstk; // push
bb->active = 1;
bstk = bnext = bb;
// skip inactive spans from earlier or later commas
while ((bnext = (bnext->next==blist) ? 0 : bnext->next)) {
i = bnext->commas[0];
// past end of this brace
if (i>bb->commas[bb->cnt+1]) break;
// in this brace but not this selection
if (i<bb->commas[bb->idx] || i>bb->commas[bb->idx+1]) {
bnext->active = 0;
bnext->stack = 0;
// in this selection
} else break;
}
// is next span past this range?
if (!bnext || bnext->commas[0]>bb->commas[bb->idx+1]) {
// output uninterrupted span
i = bb->commas[bstk->idx]+1;
s = stpncpy(s, old+i, bb->commas[bb->idx+1]-i);
// While not sibling, output tail and pop
while (!bnext || bnext->commas[0] > bstk->commas[bstk->cnt+1]) {
if (!(bb = bstk->stack)) break;
i = bstk->commas[bstk->cnt+1]+1; // start of span
j = bb->commas[bb->idx+1]; // enclosing comma span
while (bnext) {
if (bnext->commas[0]<j) {
j = bnext->commas[0];// sibling
break;
} else if (bb->commas[bb->cnt+1]>bnext->commas[0])
bnext = (bnext->next == blist) ? 0 : bnext->next;
else break;
}
s = stpncpy(s, old+i, j-i);
// if next is sibling but parent _not_ a sibling, don't pop
if (bnext && bnext->commas[0]<bstk->stack->commas[bstk->stack->cnt+1])
break;
bstk = bstk->stack;
}
}
bb = (bnext == blist) ? 0 : bnext;
}
// Save result
expand_arg_nobrace(arg, ss, flags|FORCE_KEEP, delete);
// increment
for (bb = blist->prev; bb; bb = (bb == blist) ? 0 : bb->prev) {
if (!bb->stack) continue;
else if (++bb->idx > bb->cnt) bb->idx = 0;
else break;
}
// if increment went off left edge, done expanding
if (!bb) return llist_traverse(blist, free);
}
}
// Expand exactly one arg, returning NULL if it split.
static char *expand_one_arg(char *new, unsigned flags, struct arg_list **del)
{
struct sh_arg arg;
char *s = 0;
int i;
memset(&arg, 0, sizeof(arg));
expand_arg(&arg, new, flags, del);
if (arg.c == 1) s = *arg.v;
else if (!del) for (i = 0; i < arg.c; i++) free(arg.v[i]);
free(arg.v);
return s;
}
// return length of match found at this point (try is null terminated array)
static int anystart(char *s, char **try)
{
char *ss = s;
while (*try) if (strstart(&s, *try++)) return s-ss;
return 0;
}
// does this entire string match one of the strings in try[]
static int anystr(char *s, char **try)
{
while (*try) if (!strcmp(s, *try++)) return 1;
return 0;
}
// return length of valid prefix that could go before redirect
static int redir_prefix(char *word)
{
char *s = word;
if (*s == '{') {
for (s++; isalnum(*s) || *s=='_'; s++);
if (*s == '}' && s != word+1) s++;
else s = word;
} else while (isdigit(*s)) s++;
return s-word;
}
// TODO |&
// restore displaced filehandles, closing high filehandles they were copied to
static void unredirect(int *urd)
{
int *rr = urd+1, i;
if (!urd) return;
for (i = 0; i<*urd; i++, rr += 2) {
if (BUGBUG) dprintf(255, "urd %d %d\n", rr[0], rr[1]);
if (rr[1] != -1) {
// No idea what to do about fd exhaustion here, so Steinbach's Guideline.
dup2(rr[0], rr[1]);
close(rr[0]);
}
}
free(urd);
}
// Return next available high (>=10) file descriptor
int next_hfd()
{
int hfd;
for (; TT.hfd<=99999; TT.hfd++) if (-1 == fcntl(TT.hfd, F_GETFL)) break;
hfd = TT.hfd;
if (TT.hfd > 99999) {
hfd = -1;
if (!errno) errno = EMFILE;
}
return hfd;
}
// Perform a redirect, saving displaced filehandle to a high (>10) fd
// rd is an int array: [0] = count, followed by from/to pairs to restore later.
// If from == -1 just save to, else dup from->to after saving to.
int save_redirect(int **rd, int from, int to)
{
int cnt, hfd, *rr;
// save displaced to, copying to high (>=10) file descriptor to undo later
// except if we're saving to environment variable instead (don't undo that)
if ((hfd = next_hfd())==-1) return 1;
if (hfd != dup2(to, hfd)) hfd = -1;
else fcntl(hfd, F_SETFD, FD_CLOEXEC);
if (BUGBUG) dprintf(255, "redir from=%d to=%d hfd=%d\n", from, to, hfd);
// dup "to"
if (from != -1 && to != dup2(from, to)) {
if (hfd != -1) close(hfd);
return 1;
}
// Append undo information to redirect list so we can restore saved hfd later.
if (!((cnt = *rd ? **rd : 0)&31)) *rd = xrealloc(*rd, (cnt+33)*2*sizeof(int));
*(rr = *rd) = ++cnt;
rr[2*cnt-1] = hfd;
rr[2*cnt] = to;
return 0;
}
// Pipeline segments
struct sh_pipeline {
struct sh_pipeline *next, *prev;
int count, here, type;
struct sh_arg arg[1];
};
// scratch space (state held between calls). Don't want to make it global yet
// because this could be reentrant.
struct sh_function {
char *name;
struct sh_pipeline *pipeline;
struct double_list *expect;
// TODO: lifetime rules for arg? remember "shift" command.
struct sh_arg *arg; // arguments to function call
char *end;
};
// TODO: try to avoid prototype.
static int parse_line(char *line, struct sh_function *sp);
void free_function(struct sh_function *sp);
// TODO: waitpid(WNOHANG) to clean up zombies and catch background& ending
static void subshell_callback(void)
{
TT.subshell_env = xmprintf("@%d,%d=", getpid(), getppid());
xsetenv(TT.subshell_env, 0);
TT.subshell_env[strlen(TT.subshell_env)-1] = 0;
}
// Pass environment and command string to child shell
static int run_subshell(char *str, int len)
{
int pipes[2], pid, i;
if (pipe(pipes) || 254 != dup2(pipes[0], 254)) return 1;
close(pipes[0]);
fcntl(pipes[1], F_SETFD, FD_CLOEXEC);
pid = xpopen_setup(0, 0, subshell_callback);
close(254);
if (TT.locals)
for (i = 0; TT.locals[i]; i++) dprintf(pipes[1], "%s\n", TT.locals[i]);
dprintf(pipes[1], "%.*s\n", len, str);
close(pipes[1]);
return pid;
}
// Expand arguments and perform redirections. Return new process object with
// expanded args. This can be called from command or block context.
static struct sh_process *expand_redir(struct sh_arg *arg, int envlen, int *urd)
{
struct sh_process *pp;
char *s = s, *ss, *sss, *cv = 0;
int j, to, from, here = 0;
TT.hfd = 10;
pp = xzalloc(sizeof(struct sh_process));
pp->urd = urd;
// When we redirect, we copy each displaced filehandle to restore it later.
// Expand arguments and perform redirections
for (j = envlen; j<arg->c; j++) {
int saveclose = 0, bad = 0;
s = arg->v[j];
// Handle <() >() redirectionss
if ((*s == '<' || *s == '>') && s[1] == '(') {
int pipes[2], *uu = 0, dd;
// Grab subshell data
if (pipe(pipes)) {
perror_msg_raw(s);
pp->exit = 1;
return pp;
}
// Perform input or output redirect and launch process
dd = *s == '<';
save_redirect(&uu, pipes[dd], dd);
close(pipes[dd]);
run_subshell(s+2, strlen(s+2)-1); // ignore errors, don't track
unredirect(uu);
save_redirect(&urd, -1, pipes[!dd]);
// bash uses /dev/fd/%d which requires /dev/fd to be a symlink to
// /proc/self/fd so we just produce that directly.
add_arg(&pp->delete, ss = xmprintf("/proc/self/fd/%d", pipes[!dd]));
array_add(&pp->arg.v, pp->arg.c++, ss);
continue;
}
// Is this a redirect? s = prefix, ss = operator
ss = s + redir_prefix(arg->v[j]);
sss = ss + anystart(ss, (void *)redirectors);
if (ss == sss) {
// Nope: save/expand argument and loop
expand_arg(&pp->arg, s, 0, &pp->delete);
continue;
} else if (j+1 >= arg->c) {
// redirect needs one argument
s = "\\n";
break;
}
sss = arg->v[++j];
// It's a redirect: for [to]<from s = start of [to], ss = <, sss = from
if (isdigit(*s) && ss-s>5) break;
// expand arguments for everything but << and <<-
if (strncmp(ss, "<<", 2) && ss[2] != '<' &&
!(sss = expand_one_arg(sss, NO_PATH, &pp->delete)))
{
s = sss;
break; // arg splitting here is an error
}
// Parse the [fd] part of [fd]<name
to = *ss != '<';
if (isdigit(*s)) to = atoi(s);
else if (*s == '{') {
// when we close a filehandle, we _read_ from {var}, not write to it
if ((!strcmp(ss, "<&") || !strcmp(ss, ">&")) && !strcmp(sss, "-")) {
if (!(ss = getvarlen(s+1, ss-s-2))) break;
to = atoi(ss); // TODO trailing garbage?
if (save_redirect(&pp->urd, -1, to)) break;
close(to);
continue;
// record high file descriptor in {to}<from environment variable
} else {
// we don't save this, it goes in the env var and user can close it.
if (-1 == (to = next_hfd())) break;
cv = xmprintf("%.*s=%d", (int)(ss-s-1), s+1, to);
}
}
// HERE documents?
if (!strcmp(ss, "<<<") || !strcmp(ss, "<<-") || !strcmp(ss, "<<")) {
char *tmp = getvar("TMPDIR");
int i, len, zap = (ss[2] == '-'), x = !ss[strcspn(ss, "\"'")];
// store contents in open-but-deleted /tmp file.
tmp = xmprintf("%s/sh-XXXXXX", tmp ? tmp : "/tmp");
if ((from = mkstemp(tmp))>=0) {
if (unlink(tmp)) bad++;
// write contents to file (if <<< else <<) then lseek back to start
else if (ss[2] == '<') {
if (x) sss = expand_one_arg(sss, NO_PATH|NO_SPLIT, 0);
len = strlen(sss);
if (len != writeall(from, sss, len)) bad++;
if (x) free(sss);
} else {
struct sh_arg *hh = arg+here++;
for (i = 0; i<hh->c; i++) {
ss = hh->v[i];
sss = 0;
// expand_parameter, commands, and arithmetic
if (x) ss = sss = expand_one_arg(ss,
NO_PATH|NO_SPLIT|NO_BRACE|NO_TILDE|NO_QUOTE, 0);
while (zap && *ss == '\t') ss++;
x = writeall(from, ss, len = strlen(ss));
free(sss);
if (len != x) break;
}
if (i != hh->c) bad++;
}
if (!bad && lseek(from, 0, SEEK_SET)) bad++;
if (bad) close(from);
} else bad++;
free(tmp);
if (bad) break;
// from is fd<<2 (new fd to dup2() after vfork()) plus
// 2 if we should close(from>>2) after dup2(from>>2, to),
// 1 if we should close but dup for nofork recovery (ala <&2-)
// Handle file descriptor duplication/close (&> &>> <& >& with number or -)
// These redirect existing fd so nothing to open()
} else if (strchr(ss, '&')) {
// is there an explicit fd?
for (ss = sss; isdigit(*ss); ss++);
if (ss-sss>5 || (*ss && (*ss != '-' || ss[1]))) {
// bad fd
s = sss;
break;
}
from = (ss==sss) ? to : atoi(sss);
saveclose = 2-(*ss == '-');
} else {
// Permissions to open external file with: < > >> <& >& <> >| &>> &>
if (!strcmp(ss, "<>")) from = O_CREAT|O_RDWR;
else if (strstr(ss, ">>")) from = O_CREAT|O_APPEND;
else {
from = (*ss != '<') ? O_CREAT|O_WRONLY|O_TRUNC : O_RDONLY;
if (!strcmp(ss, ">") && (TT.options&SH_NOCLOBBER)) {
struct stat st;
// Not _just_ O_EXCL: > /dev/null allowed
if (stat(sss, &st) || !S_ISREG(st.st_mode)) from |= O_EXCL;
}
}
// we expect /dev/fd/# and /dev/{stdin,stdout,stderr} to be in /dev
// TODO: /dev/{tcp,udp}/host/port
// Open the file
if (-1 == (from = xcreate(sss, from|WARN_ONLY, 0666))) break;
}
// perform redirect, saving displaced "to".
if (save_redirect(&pp->urd, from, to)) bad++;
// Do we save displaced "to" in env variable instead of undo list?
if (cv) {
--*pp->urd;
setvar(cv, TAKE_MEM);
cv = 0;
}
if ((saveclose&1) && save_redirect(&pp->urd, -1, from)) bad++;
if (!(saveclose&2)) close(from);
if (bad) break;
}
// didn't parse everything?
if (j != arg->c) {
syntax_err("bad %s", s);
if (!pp->exit) pp->exit = 1;
free(cv);
}
return pp;
}
// Execute a single command
static struct sh_process *run_command(struct sh_arg *arg)
{
struct sh_process *pp;
struct toy_list *tl;
int envlen, j;
char *s;
// Grab leading variable assignments
for (envlen = 0; envlen<arg->c; envlen++) {
s = arg->v[envlen];
for (j=0; s[j] && (s[j]=='_' || !ispunct(s[j])); j++);
if (!j || s[j] != '=') break;
}
// expand arguments and perform redirects
pp = expand_redir(arg, envlen, 0);
if (BUGBUG) { int i; dprintf(255, "envlen=%d arg->c=%d run=", envlen, arg->c); for (i=0; i<pp->arg.c; i++) dprintf(255, "'%s' ", pp->arg.v[i]); dprintf(255, "\n"); }
// perform assignments locally if there's no command
if (envlen == arg->c) {
for (j = 0; j<envlen; j++) {
s = expand_one_arg(arg->v[j], NO_PATH|NO_SPLIT, 0);
setvar(s, TAKE_MEM*(s!=arg->v[j]));
}
// Do nothing if nothing to do
} else if (pp->exit || !pp->arg.v);
else if (!strcmp(*pp->arg.v, "((")) {
printf("Math!\n");
// TODO: handle ((math))
// TODO: call functions()
// Is this command a builtin that should run in this process?
} else if ((tl = toy_find(*pp->arg.v))
&& (tl->flags & (TOYFLAG_NOFORK|TOYFLAG_MAYFORK)))
{
struct toy_context temp;
sigjmp_buf rebound;
// This fakes lots of what toybox_main() does.
memcpy(&temp, &toys, sizeof(struct toy_context));
memset(&toys, 0, sizeof(struct toy_context));
if (!sigsetjmp(rebound, 1)) {
toys.rebound = &rebound;
toy_init(tl, pp->arg.v); // arg.v must be null terminated
tl->toy_main();
xflush(0);
}
pp->exit = toys.exitval;
if (toys.optargs != toys.argv+1) free(toys.optargs);
if (toys.old_umask) umask(toys.old_umask);
memcpy(&toys, &temp, sizeof(struct toy_context));
} else {
char **env = 0, **old = environ, *ss, *sss;
int kk, ll;
// Assign leading environment variables
if (envlen) {
kk = 0;
if (environ) while (environ[kk]) kk++;
if (kk) env = xmemdup(environ, sizeof(char *)*(kk+33));
for (j = 0; j<envlen; j++) {
sss = expand_one_arg(arg->v[j], NO_PATH|NO_SPLIT, &pp->delete);
for (ll = 0; ll<kk; ll++) {
for (s = sss, ss = env[ll]; *s == *ss && *s != '='; s++, ss++);
if (*s != '=') continue;
env[ll] = sss;
break;
}
if (ll == kk) array_add(&env, kk, sss);
}
environ = env;
}
if (-1 == (pp->pid = xpopen_both(pp->arg.v, 0)))
perror_msg("%s: vfork", *pp->arg.v);
// Restore environment variables
environ = old;
free(env);
}
// cleanup process
unredirect(pp->urd);
return pp;
}
static void free_process(void *ppp)
{
struct sh_process *pp = ppp;
llist_traverse(pp->delete, llist_free_arg);
free(pp);
}
// parse next word from command line. Returns end, or 0 if need continuation
// caller eats leading spaces
static char *parse_word(char *start)
{
int i, quote = 0, q, qc = 0;
char *end = start, *s;
// Things we should only return at the _start_ of a word
if (strstart(&end, "<(") || strstart(&end, ">(")) toybuf[quote++]=')';
// Redirections. 123<<file- parses as 2 args: "123<<" "file-".
s = end + redir_prefix(end);
if ((i = anystart(s, (void *)redirectors))) s += i;
if (s != end) return (end == start) ? s : end;
// (( is a special quote at the start of a word
if (strstart(&end, "((")) toybuf[quote++] = 255;
// find end of this word
while (*end) {
i = 0;
// barf if we're near overloading quote stack (nesting ridiculously deep)
if (quote>4000) {
syntax_err("tilt");
return (void *)1;
}
// Handle quote contexts
if ((q = quote ? toybuf[quote-1] : 0)) {
// when waiting for parentheses, they nest
if ((q == ')' || q == '\xff') && (*end == '(' || *end == ')')) {
if (*end == '(') qc++;
else if (qc) qc--;
else if (q == '\xff') {
// (( can end with )) or retroactively become two (( if we hit one )
if (strstart(&end, "))")) quote--;
else return start+1;
} else if (*end == ')') quote--;
end++;
// end quote?
} else if (*end == q) quote--, end++;
// single quote claims everything
else if (q == '\'') end++;
else i++;
// loop if we already handled a symbol
if (!i) continue;
} else {
// Things that only matter when unquoted
if (isspace(*end)) break;
if (*end == ')') return end+(start==end);
// Flow control characters that end pipeline segments
s = end + anystart(end, (char *[]){";;&", ";;", ";&", ";", "||",
"|&", "|", "&&", "&", "(", ")", 0});
if (s != end) return (end == start) ? s : end;
}
// Things the same unquoted or in most non-single-quote contexts
// start new quote context?
if (strchr("\"'`", *end)) toybuf[quote++] = *end++;
// backslash escapes
else if (*end == '\\') {
if (!end[1] || (end[1]=='\n' && !end[2])) return 0;
end += 2;
} else if (*end++ == '$') {
if (-1 != (i = stridx("({[", *end))) {
toybuf[quote++] = ")}]"[i];
end++;
}
}
}
return quote ? 0 : end;
}
// if then fi for while until select done done case esac break continue return
// Free one pipeline segment.
void free_pipeline(void *pipeline)
{
struct sh_pipeline *pl = pipeline;
int i, j;
if (pl) for (j=0; j<=pl->count; j++) {
for (i = 0; i<=pl->arg->c; i++) free(pl->arg[j].v[i]);
free(pl->arg[j].v);
}
free(pl);
}
// Return end of current block, or NULL if we weren't in block and fell off end.
struct sh_pipeline *block_end(struct sh_pipeline *pl)
{
int i = 0;
// TODO: should this be inlined into type 1 processing to set blk->end and
// then everything else use that?
while (pl) {
if (pl->type == 1 || pl->type == 'f') i++;
else if (pl->type == 3) if (--i<1) break;
pl = pl->next;
}
return 0;
}
void free_function(struct sh_function *sp)
{
llist_traverse(sp->pipeline, free_pipeline);
llist_traverse(sp->expect, free);
memset(sp, 0, sizeof(struct sh_function));
}
// TODO this has to add to a namespace context. Functions within functions...
struct sh_pipeline *add_function(char *name, struct sh_pipeline *pl)
{
dprintf(2, "stub add_function");
return block_end(pl->next);
}
// Add a line of shell script to a shell function. Returns 0 if finished,
// 1 to request another line of input (> prompt), -1 for syntax err
static int parse_line(char *line, struct sh_function *sp)
{
char *start = line, *delete = 0, *end, *last = 0, *s, *ex, done = 0;
struct sh_pipeline *pl = sp->pipeline ? sp->pipeline->prev : 0;
struct sh_arg *arg = 0;
long i;
// Resume appending to last statement?
if (pl) {
arg = pl->arg;
// Extend/resume quoted block
if (arg->c<0) {
delete = start = xmprintf("%s%s", arg->v[arg->c = (-arg->c)-1], start);
free(arg->v[arg->c]);
arg->v[arg->c] = 0;
// is a HERE document in progress?
} else if (pl->count != pl->here) {
arg += 1+pl->here;
// Match unquoted EOF.
for (s = line, end = arg->v[arg->c]; *s && *end; s++, i++) {
s += strspn(s, "\\\"'");
if (*s != *end) break;
}
if (!*s && !*end) {
// Add this line
array_add(&arg->v, arg->c++, xstrdup(line));
array_add(&arg->v, arg->c, arg->v[arg->c]);
arg->c++;
// EOF hit, end HERE document
} else {
arg->v[arg->c] = 0;
pl->here++;
}
start = 0;
// Nope, new segment
} else pl = 0;
}
// Parse words, assemble argv[] pipelines, check flow control and HERE docs
if (start) for (;;) {
ex = sp->expect ? sp->expect->prev->data : 0;
// Look for << HERE redirections in completed pipeline segment
if (pl && pl->count == -1) {
pl->count = 0;
arg = pl->arg;
// find arguments of the form [{n}]<<[-] with another one after it
for (i = 0; i<arg->c; i++) {
s = arg->v[i] + redir_prefix(arg->v[i]);
// TODO <<< is funky
// argc[] entries removed from main list? Can have more than one?
if (strcmp(s, "<<") && strcmp(s, "<<-") && strcmp(s, "<<<")) continue;
if (i+1 == arg->c) goto flush;
// Add another arg[] to the pipeline segment (removing/readding to list
// because realloc can move pointer)
dlist_lpop(&sp->pipeline);
pl = xrealloc(pl, sizeof(*pl) + ++pl->count*sizeof(struct sh_arg));
dlist_add_nomalloc((void *)&sp->pipeline, (void *)pl);
// queue up HERE EOF so input loop asks for more lines.
arg[pl->count].v = xzalloc(2*sizeof(void *));
arg[pl->count].v[0] = arg->v[++i];
arg[pl->count].v[1] = 0;
arg[pl->count].c = 0;
if (s[2] == '<') pl->here++; // <<< doesn't load more data
}
pl = 0;
}
if (done) break;
s = 0;
// skip leading whitespace/comment here to know where next word starts
while (isspace(*start)) ++start;
if (*start=='#') while (*start && *start != '\n') ++start;
// Parse next word and detect overflow (too many nested quotes).
if ((end = parse_word(start)) == (void *)1)
goto flush;
// Is this a new pipeline segment?
if (!pl) {
pl = xzalloc(sizeof(struct sh_pipeline));
arg = pl->arg;
dlist_add_nomalloc((void *)&sp->pipeline, (void *)pl);
}
// Do we need to request another line to finish word (find ending quote)?
if (!end) {
// Save unparsed bit of this line, we'll need to re-parse it.
array_add(&arg->v, arg->c++, xstrndup(start, strlen(start)));
arg->c = -arg->c;
free(delete);
return 1;
}
// Ok, we have a word. What does it _mean_?
// Did we hit end of line or ) outside a function declaration?
// ) is only saved at start of a statement, ends current statement
if (end == start || (arg->c && *start == ')' && pl->type!='f')) {
if (!arg->v) array_add(&arg->v, arg->c, 0);
if (pl->type == 'f' && arg->c<3) {
s = "function()";
goto flush;
}
// "for" on its own line is an error.
if (arg->c == 1 && ex && !memcmp(ex, "do\0A", 4)) {
s = "newline";
goto flush;
}
// don't save blank pipeline segments
if (!arg->c) free_pipeline(dlist_lpop(&sp->pipeline));
// stop at EOL, else continue with new pipeline segment for )
if (end == start) done++;
pl->count = -1;
last = 0;
continue;
}
// Save argument (strdup) and check for flow control
array_add(&arg->v, arg->c, s = xstrndup(start, end-start));
start = end;
if (strchr(";|&", *s)) {
// flow control without a statement is an error
if (!arg->c) goto flush;
// treat ; as newline so we don't have to check both elsewhere.
if (!strcmp(s, ";")) {
arg->v[arg->c] = 0;
free(s);
s = 0;
// ;; and friends only allowed in case statements
} else if (*s == ';' && (!ex || strcmp(ex, "esac"))) goto flush;
last = s;
pl->count = -1;
continue;
} else arg->v[++arg->c] = 0;
// is a function() in progress?
if (arg->c>1 && !strcmp(s, "(")) pl->type = 'f';
if (pl->type=='f') {
if (arg->c == 2 && strcmp(s, "(")) goto flush;
if (arg->c == 3) {
if (strcmp(s, ")")) goto flush;
// end function segment, expect function body
pl->count = -1;
last = 0;
dlist_add(&sp->expect, "}");
dlist_add(&sp->expect, 0);
dlist_add(&sp->expect, "{");
continue;
}
// a for/select must have at least one additional argument on same line
} else if (ex && !memcmp(ex, "do\0A", 4)) {
// Sanity check and break the segment
if (strncmp(s, "((", 2) && strchr(s, '=')) goto flush;
pl->count = -1;
sp->expect->prev->data = "do\0C";
continue;
// flow control is the first word of a pipeline segment
} else if (arg->c>1) continue;
// Do we expect something that _must_ come next? (no multiple statements)
if (ex) {
// When waiting for { it must be next symbol, but can be on a new line.
if (!strcmp(ex, "{")) {
if (strcmp(s, "{")) goto flush;
free(arg->v[--arg->c]); // don't save the {, function starts the block
free(dlist_lpop(&sp->expect));
continue;
// The "test" part of for/select loops can have (at most) one "in" line,
// for {((;;))|name [in...]} do
} else if (!memcmp(ex, "do\0C", 4)) {
if (strcmp(s, "do")) {
// can only have one "in" line between for/do, but not with for(())
if (!pl->prev->type) goto flush;
if (!strncmp(pl->prev->arg->v[1], "((", 2)) goto flush;
else if (strcmp(s, "in")) goto flush;
continue;
}
}
}
// start of a new block?
// for/select requires variable name on same line, can't break segment yet
if (!strcmp(s, "for") || !strcmp(s, "select")) {
if (!pl->type) pl->type = 1;
dlist_add(&sp->expect, "do\0A");
continue;
}
end = 0;
if (!strcmp(s, "if")) end = "then";
else if (!strcmp(s, "while") || !strcmp(s, "until")) end = "do\0B";
else if (!strcmp(s, "case")) end = "esac";
else if (!strcmp(s, "{")) end = "}";
else if (!strcmp(s, "[[")) end = "]]";
else if (!strcmp(s, "(")) end = ")";
// Expecting NULL means a statement: I.E. any otherwise unrecognized word
else if (sp->expect && !ex) {
free(dlist_lpop(&sp->expect));
continue;
} else if (!ex) goto check;
// Did we start a new statement?
if (end) {
pl->type = 1;
// Only innermost statement needed in { { { echo ;} ;} ;} and such
if (sp->expect && !sp->expect->prev->data) free(dlist_lpop(&sp->expect));
// If we got here we expect a specific word to end this block: is this it?
} else if (!strcmp(s, ex)) {
// can't "if | then" or "while && do", only ; & or newline works
if (last && (strcmp(ex, "then") || strcmp(last, "&"))) {
s = end;
goto flush;
}
free(dlist_lpop(&sp->expect));
pl->type = anystr(s, (char *[]){"fi", "done", "esac", "}", "]]", ")", 0})
? 3 : 2;
// if it's a multipart block, what comes next?
if (!strcmp(s, "do")) end = "done";
else if (!strcmp(s, "then")) end = "fi\0A";
// fi could have elif, which queues a then.
} else if (!strcmp(ex, "fi")) {
if (!strcmp(s, "elif")) {
free(dlist_lpop(&sp->expect));
end = "then";
// catch duplicate else while we're here
} else if (!strcmp(s, "else")) {
if (ex[3] != 'A') {
s = "2 else";
goto flush;
}
free(dlist_lpop(&sp->expect));
end = "fi\0B";
}
}
// Do we need to queue up the next thing to expect?
if (end) {
if (!pl->type) pl->type = 2;
dlist_add(&sp->expect, end);
dlist_add(&sp->expect, 0); // they're all preceded by a statement
pl->count = -1;
}
check:
// syntax error check: these can't be the first word in an unexpected place
if (!pl->type && anystr(s, (char *[]){"then", "do", "esac", "}", "]]", ")",
"done", "fi", "elif", "else", 0})) goto flush;
}
free(delete);
// ignore blank and comment lines
if (!sp->pipeline) return 0;
// TODO <<< has no parsing impact, why play with it here at all?
// advance past <<< arguments (stored as here documents, but no new input)
pl = sp->pipeline->prev;
while (pl->count<pl->here && pl->arg[pl->count].c<0)
pl->arg[pl->count++].c = 0;
// return if HERE document pending or more flow control needed to complete
if (sp->expect) return 1;
if (sp->pipeline && pl->count != pl->here) return 1;
if (pl->arg->v[pl->arg->c]) return 1;
// Don't need more input, can start executing.
dlist_terminate(sp->pipeline);
return 0;
flush:
if (s) syntax_err("bad %s", s);
free_function(sp);
return 0-!!s;
}
static void dump_state(struct sh_function *sp)
{
struct sh_pipeline *pl;
int q = 0;
long i;
if (sp->expect) {
struct double_list *dl;
for (dl = sp->expect; dl; dl = (dl->next == sp->expect) ? 0 : dl->next)
dprintf(255, "expecting %s\n", dl->data);
if (sp->pipeline)
dprintf(255, "pipeline count=%d here=%d\n", sp->pipeline->prev->count,
sp->pipeline->prev->here);
}
for (pl = sp->pipeline; pl ; pl = (pl->next == sp->pipeline) ? 0 : pl->next) {
for (i = 0; i<pl->arg->c; i++)
dprintf(255, "arg[%d][%ld]=%s\n", q, i, pl->arg->v[i]);
if (pl->arg->c<0) dprintf(255, "argc=%d\n", pl->arg->c);
else dprintf(255, "type=%d term[%d]=%s\n", pl->type, q++, pl->arg->v[pl->arg->c]);
}
}
void dump_filehandles(char *when)
{
int fd = open("/proc/self/fd", O_RDONLY);
DIR *dir = fdopendir(fd);
char buf[256];
if (dir) {
struct dirent *dd;
while ((dd = readdir(dir))) {
if (atoi(dd->d_name)!=fd && 0<readlinkat(fd, dd->d_name, buf,sizeof(buf)))
dprintf(2, "OPEN %s %d: %s = %s\n", when, getpid(), dd->d_name, buf);
}
closedir(dir);
}
close(fd);
}
/* Flow control statements:
if/then/elif/else/fi, for select while until/do/done, case/esac,
{/}, [[/]], (/), function assignment
*/
static int wait_pipeline(struct sh_process *pp)
{
int rc = 0;
for (dlist_terminate(pp); pp; pp = pp->next) {
if (pp->pid) {
// TODO job control: not xwait, handle EINTR ourselves and check signals
pp->exit = xwaitpid(pp->pid);
pp->pid = 0;
}
// TODO handle set -o pipefail here
rc = pp->exit;
}
return rc;
}
static int pipe_segments(char *ctl, int *pipes, int **urd)
{
unredirect(*urd);
*urd = 0;
// Did the previous pipe segment pipe input into us?
if (*pipes != -1) {
save_redirect(urd, *pipes, 0);
close(*pipes);
*pipes = -1;
}
// are we piping output to the next segment?
if (ctl && *ctl == '|' && ctl[1] != '|') {
if (pipe(pipes)) {
perror_msg("pipe");
// TODO record pipeline rc
// TODO check did not reach end of pipeline after loop
return 1;
}
if (pipes[1] != 1) {
save_redirect(urd, pipes[1], 1);
close(pipes[1]);
}
fcntl(*pipes, F_SETFD, FD_CLOEXEC);
}
return 0;
}
static struct sh_pipeline *skip_andor(int rc, struct sh_pipeline *pl)
{
char *ctl = pl->arg->v[pl->arg->c];
// For && and || skip pipeline segment(s) based on return code
while (ctl && ((!strcmp(ctl, "&&") && rc) || (!strcmp(ctl, "||") && !rc))) {
if (!pl->next || pl->next->type == 2 || pl->next->type == 3) break;
pl = pl->type ? block_end(pl) : pl->next;
ctl = pl ? pl->arg->v[pl->arg->c] : 0;
}
return pl;
}
// run a parsed shell function. Handle flow control blocks and characters,
// setup pipes and block redirection, break/continue, call builtins,
// vfork/exec external commands.
static void run_function(struct sh_function *sp)
{
struct sh_pipeline *pl = sp->pipeline, *end;
struct blockstack {
struct blockstack *next;
struct sh_pipeline *start, *end;
struct sh_process *pin; // processes piping into this block
int run, loop, *urd, pout;
struct sh_arg farg; // for/select arg stack
struct arg_list *fdelete; // farg's cleanup list
char *fvar; // for/select's iteration variable name
} *blk = 0, *new;
struct sh_process *pplist = 0; // processes piping into current level
int *urd = 0, pipes[2] = {-1, -1};
long i;
// TODO can't free sh_process delete until ready to dispose else no debug output
// iterate through pipeline segments
while (pl) {
char *s = *pl->arg->v, *ss = pl->arg->v[1];
if (BUGBUG) dprintf(255, "type=%d %s %s\n", pl->type, pl->arg->v[0], pl->arg->v[pl->arg->c]);
// Is this an executable segment?
if (!pl->type) {
struct sh_arg *arg = pl->arg;
char *ctl = arg->v[arg->c];
// Skip disabled block
if (blk && !blk->run) {
while (pl->next && !pl->next->type) pl = pl->next;
continue;
}
if (pipe_segments(ctl, pipes, &urd)) break;
// If we just started a new pipeline, implicit parentheses (subshell)
// TODO: "echo | read i" is backgroundable with ctrl-Z despite read = builtin.
// probably have to inline run_command here to do that? Implicit ()
// also "X=42 | true; echo $X" doesn't get X.
// TODO: bash supports "break &" and "break > file". No idea why.
// Is it a flow control jump? These aren't handled as normal builtins
// because they move *pl to other pipeline segments which is local here.
if (!strcmp(s, "break") || !strcmp(s, "continue")) {
// How many layers to peel off?
i = ss ? atol(ss) : 0;
if (i<1) i = 1;
if (!blk || pl->arg->c>2 || ss[strspn(ss, "0123456789")]) {
syntax_err("bad %s", s);
break;
}
i = atol(ss);
if (!i) i++;
while (i && blk) {
if (--i && *s == 'c') {
pl = blk->start;
break;
}
pl = blk->end;
// TODO collate end_block logic
// if ending a block, free, cleanup redirects and pop stack.
llist_traverse(blk->fdelete, free);
unredirect(blk->urd);
if (*pipes) close(*pipes);
*pipes = blk->pout;
free(llist_pop(&blk));
}
if (i) {
syntax_err("break outside loop");
break;
}
pl = pl->next;
continue;
// Parse and run next command
} else {
// TODO: "echo | read i" is backgroundable with ctrl-Z despite read = builtin.
// probably have to inline run_command here to do that? Implicit ()
// also "X=42 | true; echo $X" doesn't get X.
dlist_add_nomalloc((void *)&pplist, (void *)run_command(arg));
}
if (*pipes == -1) {
toys.exitval = wait_pipeline(pplist);
llist_traverse(pplist, free_process);
pplist = 0;
pl = skip_andor(toys.exitval, pl);
}
// Start of flow control block?
} else if (pl->type == 1) {
// are we entering this block (rather than looping back to it)?
if (!blk || blk->start != pl) {
struct sh_process *pp;
// If it's a nested block we're not running, skip ahead.
end = block_end(pl->next);
if (blk && !blk->run) {
pl = end;
if (pl) pl = pl->next;
continue;
}
// If previous piped into this block, save context until block end
if (pipe_segments(0, pipes, &urd)) break;
// It's a new block we're running, save context and add it to the stack.
new = xzalloc(sizeof(*blk));
new->next = blk;
blk = new;
blk->start = pl;
blk->end = end;
blk->run = 1;
// save context until block end
blk->pout = *pipes;
blk->urd = urd;
urd = 0;
*pipes = -1;
// Perform redirects listed at end of block
pp = expand_redir(blk->end->arg, 0, blk->urd);
blk->urd = pp->urd;
if (pp->arg.c) perror_msg("unexpected %s", *pp->arg.v);
llist_traverse(pp->delete, free);
if (pp->arg.c) break;
free(pp);
}
// What flow control statement is this?
// TODO ( subshell
// if/then/elif/else/fi, while until/do/done - no special handling needed
// for select/do/done
if (!strcmp(s, "for") || !strcmp(s, "select")) {
if (blk->loop);
else if (!strncmp(blk->fvar = ss, "((", 2)) {
blk->loop = 1;
dprintf(2, "TODO skipped init for((;;)), need math parser\n");
} else {
// populate blk->farg with expanded arguments
if (!pl->next->type) {
for (i = 1; i<pl->next->arg->c; i++)
expand_arg(&blk->farg, pl->next->arg->v[i], 0, &blk->fdelete);
} else expand_arg(&blk->farg, "\"$@\"", 0, &blk->fdelete);
}
pl = pl->next;
}
/* TODO
case/esac
{/}
[[/]]
(/)
((/))
function/}
*/
// gearshift from block start to block body (end of flow control test)
} else if (pl->type == 2) {
// Handle if statement
if (!strcmp(s, "then")) blk->run = blk->run && !toys.exitval;
else if (!strcmp(s, "else") || !strcmp(s, "elif")) blk->run = !blk->run;
else if (!strcmp(s, "do")) {
ss = *blk->start->arg->v;
if (!strcmp(ss, "while")) blk->run = blk->run && !toys.exitval;
else if (!strcmp(ss, "until")) blk->run = blk->run && toys.exitval;
else if (blk->loop >= blk->farg.c) {
blk->run = 0;
pl = block_end(pl);
continue;
} else if (!strncmp(blk->fvar, "((", 2)) {
dprintf(2, "TODO skipped running for((;;)), need math parser\n");
} else setvar(xmprintf("%s=%s", blk->fvar, blk->farg.v[blk->loop++]),
TAKE_MEM);
}
// end of block, may have trailing redirections and/or pipe
} else if (pl->type == 3) {
// repeating block?
if (blk->run && !strcmp(s, "done")) {
pl = blk->start;
continue;
}
// TODO goto "break" above instead of copying it here?
// if ending a block, free, cleanup redirects, and pop stack.
// needing to unredirect(urd) or close(pipes[0]) here would be syntax err
llist_traverse(blk->fdelete, free);
unredirect(blk->urd);
*pipes = blk->pout;
free(llist_pop(&blk));
} else if (pl->type == 'f') pl = add_function(s, pl);
pl = pl->next;
}
// did we exit with unfinished stuff?
if (*pipes != -1) close(*pipes);
if (pplist) {
toys.exitval = wait_pipeline(pplist);
llist_traverse(pplist, free_process);
}
unredirect(urd);
// Cleanup from syntax_err();
while (blk) {
llist_traverse(blk->fdelete, free);
unredirect(blk->urd);
free(llist_pop(&blk));
}
return;
}
// Parse and run a self-contained command line with no prompt/continuation
static int sh_run(char *new)
{
struct sh_function scratch;
int rc;
memset(&scratch, 0, sizeof(struct sh_function));
if (!parse_line(new, &scratch)) run_function(&scratch);
free_function(&scratch);
rc = toys.exitval;
toys.exitval = 0;
return rc;
}
// Print prompt to stderr, parsing escapes
// Truncated to 4k at the moment, waiting for somebody to complain.
static void do_prompt(char *prompt)
{
char *s, *ss, c, cc, *pp = toybuf;
int len, ll;
if (!prompt) prompt = "\\$ ";
while ((len = sizeof(toybuf)-(pp-toybuf))>0 && *prompt) {
c = *(prompt++);
if (c=='!') {
if (*prompt=='!') prompt++;
else {
pp += snprintf(pp, len, "%ld", TT.lineno);
continue;
}
} else if (c=='\\') {
cc = *(prompt++);
if (!cc) {
*pp++ = c;
break;
}
// \nnn \dD{}hHjlstT@AuvVwW!#$
// Ignore bash's "nonprintable" hack; query our cursor position instead.
if (cc=='[' || cc==']') continue;
else if (cc=='$') *pp++ = getuid() ? '$' : '#';
else if (cc=='h' || cc=='H') {
*pp = 0;
gethostname(pp, len);
pp[len-1] = 0;
if (cc=='h' && (s = strchr(pp, '.'))) *s = 0;
pp += strlen(pp);
} else if (cc=='s') {
s = getbasename(*toys.argv);
while (*s && len--) *pp++ = *s++;
} else if (cc=='w') {
if ((s = getvar("PWD"))) {
if ((ss = getvar("HOME")) && strstart(&s, ss)) {
*pp++ = '~';
if (--len && *s!='/') *pp++ = '/';
len--;
}
if (len>0) {
ll = strlen(s);
pp = stpncpy(pp, s, ll>len ? len : ll);
}
}
} else if (!(c = unescape(cc))) {
*pp++ = '\\';
if (--len) *pp++ = c;
} else *pp++ = c;
} else *pp++ = c;
}
len = pp-toybuf;
if (len>=sizeof(toybuf)) len = sizeof(toybuf);
writeall(2, toybuf, len);
}
// sanitize environment and handle nommu subshell handoff
void subshell_imports(void)
{
int to, from, pid = 0, ppid = 0, len;
struct stat st;
FILE *fp;
char *s;
// Ensure environ copied and toys.envc set, and clean out illegal entries
xunsetenv("");
for (to = from = 0; (s = environ[from]); from++) {
// If nommu subshell gets handoff
if (!CFG_TOYBOX_FORK && !toys.stacktop) {
len = 0;
sscanf(s, "@%d,%d%n", &pid, &ppid, &len);
if (len && s[len]) pid = ppid = 0;
}
// Filter out non-shell variable names
for (len = 0; s[len] && ((s[len] == '_') || !ispunct(s[len])); len++);
if (s[len] == '=') environ[to++] = environ[from];
}
environ[toys.optc = to] = 0;
//TODO indexed array,associative array,integer,local,nameref,readonly,uppercase
// if (s+1<ss && strchr("aAilnru", *s)) {
// sanity check: magic env variable, pipe status
if (CFG_TOYBOX_FORK || toys.stacktop || pid != getpid() || ppid != getppid())
return;
if (fstat(254, &st) || !S_ISFIFO(st.st_mode)) error_exit(0);
fcntl(254, F_SETFD, FD_CLOEXEC);
fp = fdopen(254, "r");
// This is not efficient, could array_add the local vars.
// TODO implicit exec when possible
while ((s = xgetline(fp, 0))) to = sh_run(s);
fclose(fp);
toys.exitval = to;
xexit();
}
void sh_main(void)
{
FILE *f;
char *new;
struct sh_function scratch;
int prompt = 0;
TT.hfd = 10;
signal(SIGPIPE, SIG_IGN);
// Ensure environ copied and toys.envc set
xunsetenv("");
// TODO: traverse and unset illegal environment variables named "$" and such
// TODO euid stuff?
// TODO read profile, read rc
// if (!FLAG(noprofile)) { }
// Set local variable $HOME to user's login path
if (!(new = getenv("HOME"))) {
struct passwd *pw = getpwuid(getuid());
setvar(xmprintf("HOME=%s", (pw && *pw->pw_dir)?pw->pw_dir:"/"), TAKE_MEM);
}
sh_run("cd .");
if (BUGBUG) { int fd = open("/dev/tty", O_RDWR); dup2(fd, 255); close(fd); }
// Is this an interactive shell?
// if (FLAG(i) || (!FLAG(c)&&(FLAG(S)||!toys.optc) && isatty(0) && isatty(1)))
// Set up signal handlers and grab control of this tty.
// Read environment for exports from parent shell
subshell_imports();
memset(&scratch, 0, sizeof(scratch));
if (TT.command) f = fmemopen(TT.command, strlen(TT.command), "r");
else if (*toys.optargs) f = xfopen(*toys.optargs, "r");
else {
f = stdin;
if (isatty(0)) toys.optflags |= FLAG_i;
}
for (;;) {
// Prompt and read line
if (f == stdin) {
char *s = getenv(prompt ? "PS2" : "PS1");
if (!s) s = prompt ? "> " : (getpid() ? "\\$ " : "# ");
do_prompt(s);
} else TT.lineno++;
// TODO line editing/history
if (!(new = xgetline(f ? f : stdin, 0))) break;
// TODO if (!isspace(*new)) add_to_history(line);
// returns 0 if line consumed, command if it needs more data
prompt = parse_line(new, &scratch);
if (BUGBUG) dump_state(&scratch);
if (prompt != 1) {
// TODO: ./blah.sh one two three: put one two three in scratch.arg
if (!prompt) run_function(&scratch);
free_function(&scratch);
prompt = 0;
}
free(new);
}
if (prompt) error_exit("%ld:unfinished line"+4*!TT.lineno, TT.lineno);
toys.exitval = f && ferror(f);
clearerr(stdout);
}
/********************* shell builtin functions *************************/
#define CLEANUP_sh
#define FOR_cd
#include "generated/flags.h"
void cd_main(void)
{
char *home = getvar("HOME"), *pwd = getvar("PWD"), *dd = 0, *from, *to,
*dest = (*toys.optargs && **toys.optargs) ? *toys.optargs : "~";
int bad = 0;
// TODO: CDPATH? Really?
if (!home) home = "/";
// expand variables
if (dest) dd = expand_one_arg(dest, FORCE_COPY|NO_SPLIT, 0);
if (!dd || !*dd) {
free(dd);
dd = xstrdup("/");
}
// prepend cwd or $PWD to relative path
if (*dd != '/') {
to = 0;
from = pwd ? pwd : (to = getcwd(0, 0));
if (!from) xsetenv("PWD", "(nowhere)");
else {
from = xmprintf("%s/%s", from, dd);
free(dd);
free(to);
dd = from;
}
}
if (FLAG(P)) {
struct stat st;
char *pp;
// Does this directory exist?
if ((pp = xabspath(dd, 1)) && stat(pp, &st) && !S_ISDIR(st.st_mode))
bad++, errno = ENOTDIR;
else {
free(dd);
dd = pp;
}
} else {
// cancel out . and .. in the string
for (from = to = dd; *from;) {
if (*from=='/' && from[1]=='/') from++;
else if (*from!='/' || from[1]!='.') *to++ = *from++;
else if (!from[2] || from[2]=='/') from += 2;
else if (from[2]=='.' && (!from[3] || from[3]=='/')) {
from += 3;
while (to>dd && *--to != '/');
} else *to++ = *from++;
}
if (to == dd) to++;
if (to-dd>1 && to[-1]=='/') to--;
*to = 0;
}
if (bad || chdir(dd)) perror_msg("chdir '%s'", dd);
else {
if (pwd) xsetenv("OLD", pwd);
xsetenv("PWD", dd);
}
free(dd);
}
void exit_main(void)
{
exit(*toys.optargs ? atoi(*toys.optargs) : 0);
}