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authorRob Landley <rob@landley.net>2020-01-07 22:15:06 -0600
committerRob Landley <rob@landley.net>2020-01-07 22:15:06 -0600
commite50071809764cc581a3447fc965e26a10a179953 (patch)
tree1ecc9bf897e93be38abf3b7503d7274978f90711 /toys
parente00ab7de3c5f929adee379da555fb6c678770f28 (diff)
downloadtoybox-e50071809764cc581a3447fc965e26a10a179953.tar.gz
Bracket support in progress. Mind the dprintf()s.
Diffstat (limited to 'toys')
-rw-r--r--toys/pending/sh.c269
1 files changed, 263 insertions, 6 deletions
diff --git a/toys/pending/sh.c b/toys/pending/sh.c
index dc4b774e..4697f081 100644
--- a/toys/pending/sh.c
+++ b/toys/pending/sh.c
@@ -217,6 +217,31 @@ static char *getvar(char *s)
return getvarlen(s, strlen(s));
}
+
+
+// returns pointer to next unquoted (or double quoted if dquot) char.
+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;
+}
+
// quote removal, brace, tilde, parameter/variable, $(command),
// $((arithmetic)), split, path
#define NO_PATH (1<<0)
@@ -225,6 +250,7 @@ static char *getvar(char *s)
#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
@@ -232,18 +258,17 @@ static char *getvar(char *s)
// 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(struct sh_arg *arg, char *old, unsigned flags,
+static void expand_arg_nobrace(struct sh_arg *arg, char *old, unsigned flags,
struct arg_list **delete)
{
- char *new = old, *s, *ss, quote = 0;
+ char *new = old;
// TODO ls -l /proc/$$/fd
-// ${ $(( $( $[ $' `
-
// Tilde expansion
if (!(flags&NO_TILDE) && *new == '~') {
struct passwd *pw = 0;
+ char *s, *ss;
// first expansion so don't need to free previous new
ss = 0;
@@ -260,6 +285,8 @@ static void expand_arg(struct sh_arg *arg, char *old, unsigned flags,
new = xmprintf("%s%s", ss, s);
}
+// ${ $(( $( $[ $' ` " '
+
/*
while (*s) {
if (!quote && !(flags&NO_BRACE) && *s == '{') {
@@ -289,9 +316,9 @@ TODO this recurses
}
*/
- // We have a result. Append it.
+ // Record result.
if (old==new && (flags&FORCE_COPY)) new = xstrdup(new);
- if (old!=new && delete) {
+ if ((old!=new || (flags&FORCE_KEEP)) && delete) {
struct arg_list *al = xmalloc(sizeof(struct arg_list));
al->next = *delete;
@@ -301,6 +328,231 @@ TODO this recurses
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 debug;
+ 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++) {
+ if (!old[i += skip_quote(old+i, 0, 0)]) break;
+ if (old[i] == '{') {
+ dlist_add_nomalloc((void *)&blist,
+ (void *)(bb = xzalloc(sizeof(struct brace)+34*4)));
+dprintf(2, "{%p@%d %c\n", bb, i, bb->debug = old[i+1]);
+ bb->commas[0] = i;
+ } else if (!bb) continue;
+ else if (bb && old[i] == ',') {
+dprintf(2, ",%p@%d\t%c\n", bb, i, old[i+1]);
+ 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;
+dprintf(2, "cnt %c %d\n", bb->debug, bb->cnt);
+ } else if (bb && old[i] == '}') {
+ bb->active = bb->commas[bb->cnt+1] = i;
+ for (bnext = bb; bb && bb->active; bb = (bb==blist)?0:bb->prev);
+dprintf(2, "}[%d]%p@%d\n", bnext->cnt, bb, i);
+ // discard commaless brace
+ if (!bnext->cnt) free((blist == bnext) ? dlist_pop(&blist) : bnext);
+ }
+ }
+
+// TODO NOSPLIT with braces? (Collate with spaces?)
+ // If none, pass on verbatim
+ if (!blist) return expand_arg_nobrace(arg, old, flags, delete);
+
+dprintf(2, "got here\n");
+for (bstk = blist; bstk; bstk = (bstk->next == blist) ? 0 : bstk->next) {
+ dprintf(2, "murf %c %d %p", bstk->debug, bstk->cnt, bstk);
+ for (i = 0; i<=bstk->cnt+1; i++) dprintf(2, " %d", bstk->commas[i]);
+ dprintf(2, "\n");
+}
+
+// span from "{ to }" or ", to }" or "{ to ," uninterrupted by other spans
+// span from "{ to {" or ", to {" or "start to {"
+// span from "} to }" or "} to ," or "} to end"
+// span from } to {
+
+/*
+A prefix - because new { with no parent
+ B prefix - becaue new - in comma span
+ C span - because next after this comma span
+ E suffix - because next after this comma span
+ skipped comma span
+ J sibling -
+ K span -
+*/
+
+//the problem is we need previous bstk at _same_ level when sibling.
+//postprocess bb to next, so can't be _here.
+
+// span is active if ~parent or in parent's active comma span
+
+ // 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 (;;) {
+
+dprintf(2, "combination");
+for (bb = blist; bb; bb = (bb->next == blist) ? 0 : bb->next)
+ dprintf(2, " %c %d", bb->debug, bb->idx);
+dprintf(2, "\n");
+
+ // 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;) {
+dprintf(2, "--- start loop span %c stk %c\n", bb->debug, bstk->debug);
+ // keep prefix and push self onto stack
+ if (bstk == bb) bstk = bstk->stack; // pop self
+ i = bstk->commas[bstk->idx]+1;
+dprintf(2, "idx=%d i=%d o=%d cc=%d\n", bb->idx, i, bb->commas[0], bstk->commas[bstk->cnt+1]);
+ if (bstk->commas[bstk->cnt+1]>bb->commas[0])
+ s = stpncpy(s, old+i, bb->commas[0]-i);
+
+//murgle this is wrong for post-sibling span
+//how to distinguish enclosing stack from left sibling?
+
+//murgle: _end_ of previous segment stack output, not start.
+//but enclosing one had no comma, so no end?
+dprintf(2, "========%ld %.*s prefix for %c\n", s-ss, (int)(s-ss), ss, bb->debug);
+ // pop sibling
+ if (bstk->commas[bstk->cnt+1]<bb->commas[0]) {
+dprintf(2, "sibling pop %c to %c\n", bstk->debug, bstk->stack->debug);
+ bstk = bstk->stack;
+}
+
+ bb->stack = bstk; // push
+ bb->active = 1;
+ bstk = bnext = bb;
+dprintf(2, "pushed %c\n", bb->debug);
+dprintf(2, "bnext %p\n",bnext);
+ // skip inactive spans from earlier or later commas
+ while ((bnext = (bnext->next==blist) ? 0 : bnext->next)) {
+dprintf(2, "bnext %p\n", bnext);
+dprintf(2, "maybe %c %d %d\n", bnext->debug, bnext->commas[0], bb->commas[bb->idx]);
+ i = bnext->commas[0];
+ // past end of this brace
+ if (i>bb->commas[bb->cnt+1]) {
+dprintf(2, "exit 1 %d %d\n", i, bb->commas[bb->cnt+1]);
+ break;
+}
+dprintf(2, "bnext=%c\n", bnext->debug);
+ // 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 {
+dprintf(2, "exit 2\n");
+ break;
+}
+dprintf(2, "skipped %c because %d < %d\n", bnext->debug, bnext->commas[0], bb->commas[bb->idx]);
+ }
+dprintf(2, "bnext now %p\n", bnext);
+if (bnext) dprintf(2, "bnext=%c\n", bnext->debug);
+ // is next span past this range?
+if (bnext) dprintf(2, "bnexts=%c %c %d %d\n", bnext->debug, bb->debug, bnext->commas[0], bb->commas[bb->idx]+1);
+ if (!bnext || bnext->commas[0]>bb->commas[bb->idx+1]) {
+dprintf(2, "span %d\n", bstk->idx);
+ // output uninterrupted span
+ i = bb->commas[bstk->idx]+1;
+ s = stpncpy(s, old+i, bb->commas[bb->idx+1]-i);
+dprintf(2, "span output %d %d\n", i, bstk->commas[bstk->idx+1]);
+dprintf(2, "=======2=%ld %.*s span for %c\n", s-ss, (int)(s-ss), ss, bstk->debug);
+
+ // While not sibling, output tail and pop
+ while (!bnext || bnext->commas[0] > bstk->commas[bstk->cnt+1]) {
+dprintf(2, "bstk=%p bnext=%p\n", bstk, bnext);
+if (bnext) dprintf(2, "pop %c vs %c because %d > %d\n", bstk->debug, bnext->debug, bnext->commas[0], bstk->commas[bstk->cnt+1]);
+ if (!(bb = bstk->stack)) break;
+
+/*
+ ok, failing active span is e,f: 4th span, print nothing after it (20,20)
+ first 20: 4[cnt+1], second 20: 1[idx+1]
+ j=1[idx+1]-i=4[cnt+1]
+*/
+
+if (bnext) dprintf(2, "parent %c next %c\n", bb->debug, bnext->debug);
+ i = bstk->commas[bstk->cnt+1]+1; // start of span
+ j = bb->commas[bb->idx+1]; // enclosing comma span
+char *typetype = "tail";
+dprintf(2, "what j=%d bb->idx=%d\n", j, bb->idx);
+dprintf(2, "bnext %c %d %d\n", bnext ? bnext->debug : '.', bnext ? bnext->commas[0] : 0, bnext ? bnext->commas[1] : 0);
+if (bnext) dprintf(2, "j=%d or j=%d\n", j, bnext->commas[0]);
+
+if (bnext) dprintf(2, "%c vs %c %d %d\n", bnext->debug, bstk->debug, bnext->commas[0], bstk->stack->commas[bstk->stack->cnt+1]);
+ while (bnext) {
+ if (bnext->commas[0]<j) {
+ j = bnext->commas[0];// sibling
+ break;
+typetype="sibling";
+ } else if (bb->commas[bb->cnt+1]>bnext->commas[0])
+ bnext = (bnext->next == blist) ? 0 : bnext->next;
+ else break;
+if (bnext) dprintf(2, "bnext=%c %c nc=%d bbc=%d\n", bnext->debug, bb->debug, bnext->commas[0], bb->commas[bb->cnt+1]);
+ }
+dprintf(2, "emit %d to %d\n", i, j);
+ s = stpncpy(s, old+i, j-i);
+dprintf(2, "=======3=%ld %.*s suffix for %c is %s\n", s-ss, (int)(s-ss), ss, bstk->debug, typetype);
+
+ // 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;
+
+dprintf(2, "pop %c", bstk->debug);
+ bstk = bstk->stack;
+dprintf(2, " now %c with %p\n", bstk ? bstk->debug : '.', bnext);
+ }
+dprintf(2, "out\n");
+ }
+if (bb && bnext) dprintf(2, "advance %c to %c (%c)\n", bb->debug, bnext->debug, blist->debug);
+ bb = (bnext == blist) ? 0 : bnext;
+dprintf(2, "down\n");
+ }
+dprintf(2, "increment\n");
+ // increment
+
+
+//dprintf(1, "ss=%s\n", ss);
+ expand_arg_nobrace(arg, ss, flags|FORCE_KEEP, delete);
+
+ for (bb = blist->prev; bb; bb = (bb == blist) ? 0 : bb->prev) {
+dprintf(2, "inky %c %p\n", bb->debug, bb->stack);
+ if (!bb->stack) {
+dprintf(2, "skip\n");
+ continue;
+}
+ else if (++bb->idx > bb->cnt) {
+dprintf(2, "roll bb->idx=%d bb->cnt=%d\n", bb->idx, bb->cnt);
+ bb->idx = 0;
+}
+ else {
+dprintf(2, "Incremented %c to %d\n", bb->debug, bb->idx);
+ break;
+}
+ }
+ if (!bb) {
+ llist_traverse(blist, free);
+ return;
+ }
+ }
+}
+
+
// Expand exactly one arg, returning NULL if it split.
// If return != new you need to free it.
static char *expand_one_arg(char *new, unsigned flags, struct arg_list **del)
@@ -1646,6 +1898,11 @@ void sh_main(void)
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