diff options
| -rw-r--r-- | toys/pending/sh.c | 525 |
1 files changed, 398 insertions, 127 deletions
diff --git a/toys/pending/sh.c b/toys/pending/sh.c index 18f4edf1..1e822d7e 100644 --- a/toys/pending/sh.c +++ b/toys/pending/sh.c @@ -100,6 +100,7 @@ GLOBALS( long lineno; struct double_list functions; + unsigned options; // Running jobs. struct sh_job { @@ -122,6 +123,8 @@ GLOBALS( unsigned jobcnt; ) +#define SH_NOCLOBBER 1 // set -C + void cd_main(void) { char *dest = *toys.optargs ? *toys.optargs : getenv("HOME"); @@ -134,6 +137,18 @@ void exit_main(void) exit(*toys.optargs ? atoi(*toys.optargs) : 0); } +// like error_msg() but exit from shell scripts +void syntax_err(char *msg, ...) +{ + va_list va; + + va_start(va, msg); + verror_msg(msg, 0, va); + va_end(va); + + if (*toys.optargs) xexit(); +} + // Print prompt, parsing escapes static void do_prompt(char *prompt) { @@ -180,18 +195,12 @@ down: fflush(stdout); } -// Assign one variable -// s: key=val -// type: 0 = whatever it was before, local otherwise -void setvar(char *s, int type) -{ -// todo: expand_arg: tilde, parameter+variable expansion, command substitution, arith expansion, quote removal. No wildcards, "$@" treated like "$@". - // local, export, readonly, integer... - xsetenv(xstrdup(s), 0); -} - +// quote removal, brace, tilde, parameter/variable, $(command), +// $((arithmetic)), split, path +#define NO_PATH (1<<0) +#define NO_SPLIT (1<<1) // todo: ${name:?error} causes an error/abort here (syntax_err longjmp?) -static void expand_arg(struct sh_arg *arg, char *new) +static void expand_arg(struct sh_arg *arg, char *new, unsigned flags) { if (!(arg->c&32)) arg->v = xrealloc(arg->v, sizeof(void *)*(arg->c+33)); @@ -216,36 +225,236 @@ static void expand_arg(struct sh_arg *arg, char *new) */ } -// Execute the commands in a pipeline -static void run_command(struct sh_arg *arg) +// Assign one variable +// s: key=val +// type: 0 = whatever it was before, local otherwise +#define TAKE_MEM 0x80000000 +void setvar(char *s, unsigned type) +{ + if (type&TAKE_MEM) type ^= TAKE_MEM; + else s = xstrdup(s); + + // local, export, readonly, integer... + xsetenv(s, 0); +} + +char *getvar(char *s) +{ + return getenv(s); +} + +// return length of match found at this point +static int anyof(char *s, char **try) +{ + while (*try) { + if (strstart(&s, *try)) return strlen(*try); + try++; + } + + return 0; +} + + +// return length of valid prefix that could go before redirect +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 |& + +// Execute the commands in a pipeline segment +struct sh_process *run_command(struct sh_arg *arg, int in_rdcount, int *in_rd) { struct sh_process *pp = xzalloc(sizeof(struct sh_process)); struct toy_list *tl; + char *s, *ss, *sss; unsigned envlen, j; + int fd, here = 0, rdcount = 0, *rd = 0, hfd = 0; // Grab variable assignments for (envlen = 0; envlen<arg->c; envlen++) { - char *s = arg->v[envlen]; - for (j=0; s[j] && s[j]!='=' && s[j]!='\\'; j++); - if (s[j]!='=') break; + s = arg->v[envlen]; + for (j=0; s[j] && s[j] != '=' && s[j] != '\\'; j++); + if (s[j] != '=') break; } + + // perform assignments locally if there's no command if (envlen == arg->c) { - for (j = 0; j<envlen; j++) setvar(arg->v[j], 0); - return; + for (j = 0; j<envlen; j++) { + struct sh_arg aa; + + aa.c = 0; + expand_arg(&aa, arg->v[j], NO_PATH|NO_SPLIT); + setvar(*aa.v, TAKE_MEM); + free(aa.v); + } + free(pp); + + return 0; } -// todo: from i to envlen, need either start/end or to save a chunk -// how to set without duplicates and n^2 loop? + // We vfork() instead of fork to support nommu systems, and do + // redirection setup in the parent process. Open new filehandles + // and move them to temporary values >10. The rd[] array has pairs of + // filehandles: child replaces fd1 with fd2 via dup2() and close() after + // the vfork(). fd2 is <<1, if bottom bit set don't close it (dup instead). + // If fd2 < 0 it's a here document (parent process writes to a pipe later). + + // Expand arguments and perform redirections + for (j = envlen; j<arg->c; j++) { + + // Is this a redirect? + s = arg->v[j]; + ss = s + redir_prefix(arg->v[j]); + fd = anyof(ss, (char *[]){"<<<", "<<-", "<<", "<&", "<>", "<", ">>", ">&", + ">|", ">", "&>>", "&>", 0}); + if (!fd) { + // Nope: save/expand argument and loop + expand_arg(&pp->arg, s, 0); + continue; + } + + // Yes. Expand rd[] and find first unused filehandle >10 + if (!(rdcount&31)) rd = xrealloc(rd, (2*rdcount+64)*sizeof(int *)); + if (!hfd) + for (hfd = 10; hfd<99999; hfd++) if (-1 == fcntl(hfd, F_GETFL)) break; + + // error check: premature EOF, target fd too high, or redirect file splits + if (++j == arg->c || (isdigit(*s) && ss-s>5)) { + syntax_err("bad %s", s); + pp->exit = 1; + + return pp; + } + fd = pp->arg.c; + + // expand arguments for everything but << and <<- + if (strncmp(ss, "<<", 2) || ss[2] == '<') { + expand_arg(&pp->arg, arg->v[j], NO_PATH|(NO_SPLIT*!strcmp(ss, "<<<"))); + if (fd+1 != pp->arg.c) { + syntax_err("bad %s", s); + pp->exit = 1; + + return pp; + } + sss = pp->arg.v[--pp->arg.c]; + } else dlist_add((void *)&pp->delete, sss = xstrdup(arg->v[j])); + + // rd[] entries come in pairs: first is which fd gets redirected after + // vfork(), I.E. the [n] part of [n]<word + + if (isdigit(*ss)) fd = atoi(ss); + else if (*ss == '{') { + ss++; + // when we close a filehandle, we _read_ from {var}, not write to it + if ((!strcmp(s, "<&") || !strcmp(s, ">&")) && !strcmp(sss, "-")) { + ss = xstrndup(ss, (s-ss)-1); + sss = getvar(ss); + free(ss); + fd = -1; + if (sss) fd = atoi(sss); + if (fd<0) { + syntax_err("ambiguous %s", s); + pp->exit = 1; + + return pp; + } + if (fd>2) { + rd[2*rdcount] = fd; + rd[2*rdcount++ +1] = fd<<1; // close it + } + continue; + } else setvar(xmprintf("%.*s=%d", (int)(s-ss), ss, hfd), TAKE_MEM); + } else fd = *ss != '<'; + rd[2*rdcount] = fd; + + // at this point for [n]<word s = start of [n], ss = start of <, sss = word + + // second entry in this rd[] pair is new fd to dup2() after vfork(), + // I.E. for [n]<word the fd if you open("word"). It's stored <<1 and the + // low bit set means don't close(rd[1]) after dup2(rd[1], rd[0]); + + // fd<0 means HERE document. Canned input stored earlier, becomes pipe later + if (!strcmp(s, "<<<") || !strcmp(s, "<<-") || !strcmp(s, "<<")) { + fd = --here<<2; + if (s[2] == '-') fd += 1; // zap tabs + if (s[strcspn(s, "\"'")]) fd += 2; // it was quoted so no expansion + rd[2*rdcount++ +1] = fd; + + continue; + } + + // Handle file descriptor duplication/close (&> &>> <& >& with number or -) + if (strchr(ss, '&') && ss[2] != '>') { + char *dig = sss; + + // These redirect existing fd so nothing to open() + while (isdigit(dig)) dig++; + if (dig-sss>5) { + syntax_err("bad %s", sss); + pp->exit = 1; + + return pp; + } + +// TODO can't check if fd is open here, must do it when actual redirects happen + if (!*dig || (*dig=='-' && !dig[1])) { + rd[2*rdcount +1] = (((dig==sss) ? rd[rdcount*2] : atoi(sss))<<1) + +(*dig != '-'); + rdcount++; + + continue; + } + } + + // Permissions to open external file with: < > >> <& >& <> >| &>> &> + if (!strcmp(ss, "<>")) fd = O_CREAT|O_RDWR; + else if (strstr(ss, ">>")) fd = O_CREAT|O_APPEND; + else { + fd = (*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)) fd |= O_EXCL; + } + } + + // Open the file +// TODO: /dev/fd/# /dev/{stdin,stdout,stderr} /dev/{tcp,udp}/host/port + if (-1 == (fd = xcreate(sss, fd|WARN_ONLY, 777)) || hfd != dup2(fd, hfd)) { + pp->exit = 1; - for (j = envlen; j<arg->c; j++) expand_arg(&pp->arg, arg->v[j]); + return pp; + } + if (fd != hfd) close(fd); + rd[2*rdcount++ +1] = hfd<<1; + + // queue up a 2>&1 ? + if (strchr(ss, '&')) { + if (!(31&++rdcount)) rd = xrealloc(rd, (2*rdcount+66)*sizeof(int *)); + rd[2*rdcount] = 2; + rd[2*rdcount++ +1] = 1+(1<<1); + } + } + +// todo: ok, now _use_ in_rd[in_rdcount] and rd[rdcount]. :) - tl = toy_find(*pp->arg.v); // todo use envlen // todo: check for functions // Is this command a builtin that should run in this process? - if (tl && (tl->flags & TOYFLAG_NOFORK)) { + if ((tl = toy_find(*pp->arg.v)) && (tl->flags & TOYFLAG_NOFORK)) { struct toy_context temp; sigjmp_buf rebound; @@ -277,38 +486,14 @@ static void run_command(struct sh_arg *arg) else pp->exit = xpclose_both(pp->pid, 0); } - llist_traverse(pp->delete, free); - return; -} - -// like error_msg() but exit from shell scripts -void syntax_err(char *msg, ...) -{ - va_list va; - - va_start(va, msg); - verror_msg(msg, 0, va); - va_end(va); - - if (*toys.optargs) xexit(); -} - -// return length of match found at this point -static int anyof(char *s, char **try) -{ - while (*try) { - if (strstart(&s, *try)) return strlen(*try); - try++; - } - - return 0; + return 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; + int i, j, quote = 0; char *end = start, *s; // find end of this word @@ -331,16 +516,13 @@ static char *parse_word(char *start) // control chars. // 123<<file- parses as 2 args: "123<<" "file-". // note: >&; becomes ">&" ";" because first loop, then second loop. - s = end; - if (*s == '{') s++; - for (s = end; isdigit(*s); s++); - if (*end == '{' && *s == '}') s++; - s += anyof(s, (char *[]){"<<<", "<<-", "<<", "<&", "<>", "<", ">>", + s = end + redir_prefix(end); + j = anyof(s, (char *[]){"<<<", "<<-", "<<", "<&", "<>", "<", ">>", ">&", ">|", ">", 0}); - if (s == end || isdigit(s[-1])) - s += anyof(s, (char *[]){";;&", ";;", ";&", ";", "||", "|&", "|", - "&&", "&>>", "&>", "&", "(", ")", 0}); - if (s != end && !isdigit(*s)) return (end == start) ? s : end; + if (j) s += j; + else s = end + anyof(s, (char *[]){";;&", ";;", ";&", ";", "||", "|&", + "|", "&&", "&>>", "&>", "&", "(", ")", 0}); + if (s != end) return (end == start) ? s : end; i++; } } @@ -390,10 +572,29 @@ void argxtend(struct sh_arg *arg) // Pipeline segments struct sh_pipeline { struct sh_pipeline *next, *prev; - char count, here, type; + int count, here, type; struct sh_arg arg[1]; }; +// run a series of "command | command && command" with redirects. +struct sh_pipeline *run_pipeline(struct sh_pipeline *pl, int rdcount, int *rd) +{ + struct sh_process *pp; + + for (;;) { +// todo job control + pp = run_command(pl->arg, rdcount, rd); +//wait4(pp); + llist_traverse(pp->delete, free); + free(pp); + + if (pl->next && !pl->next->type) pl = pl->next; + else return pl; + } +} + + + // scratch space (state held between calls). Don't want to make it global yet // because this could be reentrant. struct sh_parse { @@ -415,11 +616,24 @@ void free_pipeline(void *pipeline) free(pl); } +// Return end of block corresponding to start of block +struct sh_pipeline *block_end(struct sh_pipeline *pl) +{ + int i = 0; + do { + if (pl->type == 1 || pl->type == 'f') i++; + else if (pl->type == 3) i--; + pl = pl->next; + } while (i); + + return pl; +} + // Consume a line of shell script and do what it says. Returns 0 if finished, // 1 to request another line of input (> prompt). static int parse_line(char *line, struct sh_parse *sp) { - char *start = line, *delete = 0, *end, *last = 0, *s, *ex; + 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; @@ -454,6 +668,30 @@ static int parse_line(char *line, struct sh_parse *sp) // Parse words, assemble argv[] pipelines, check flow control and HERE docs if (start) for (;;) { + + // Grab HERE document(s) from 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]); + if (strcmp(s, "<<") && strcmp(s, "<<-") && strcmp(s, "<<<")) continue; + if (i+1 == arg->c) goto flush; + + // queue up HERE EOF so input loop asks for more lines. + dlist_lpop(&sp->pipeline); + pl = xrealloc(pl, sizeof(*pl) + ++pl->count*sizeof(struct sh_arg)); + dlist_add_nomalloc((void *)&sp->pipeline, (void *)pl); + + arg[pl->count].v = xzalloc(2*sizeof(void *)); + *arg[pl->count].v = arg->v[++i]; + arg[pl->count].c = -(s[2] == '<'); // note <<< as c = -1 + } + pl = 0; + } + if (done) break; s = 0; // skip leading whitespace/comment here to know where next word starts @@ -467,7 +705,7 @@ static int parse_line(char *line, struct sh_parse *sp) if ((end = parse_word(start)) == (void *)1) goto flush; // Extend pipeline and argv[] to store result - if (!arg) { + if (!pl) { pl = xzalloc(sizeof(struct sh_pipeline)); arg = pl->arg; dlist_add_nomalloc((void *)&sp->pipeline, (void *)pl); @@ -500,59 +738,34 @@ static int parse_line(char *line, struct sh_parse *sp) if (!arg->c) free_pipeline(dlist_lpop(&sp->pipeline)); // stop at EOL, else continue with new pipeline segment for ) - if (end == start) break; - arg = 0; + if (end == start) done++; + pl->count = -1; last = 0; continue; - } else { - - // Save argument (strdup) and check for flow control - s = arg->v[arg->c] = xstrndup(start, end-start); - start = end; - if (!strchr(";|&", *s)) arg->v[++arg->c] = 0; - else { - - // 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; - } - last = s; - arg = 0; - - continue; - } } - // We just ended a pipeline segment. - - // Grab HERE document(s) - for (i = 0; i<arg->c; i++) { + // Save argument (strdup) and check for flow control + s = arg->v[arg->c] = xstrndup(start, end-start); + start = end; + if (strchr(";|&", *s)) { - // find an argument of the form [{n}]<<[-] with another one after it - s = arg->v[i]; - if (*s == '{') s++; - while (isdigit(*s)) s++; - if (*arg->v[i] == '{' && *s == '}') s++; - if (strcmp(s, "<<") && strcmp(s, "<<-")) continue; - if (i+1 == arg->c) goto flush; + // flow control without a statement is an error + if (!arg->c) goto flush; - // Got one, queue it up so input loop asks for more lines. - dlist_lpop(&sp->pipeline); - pl = xrealloc(pl, sizeof(*pl) + ++pl->count*sizeof(struct sh_arg)); - dlist_add_nomalloc((void *)&sp->pipeline, (void *)pl); + // treat ; as newline so we don't have to check both elsewhere. + if (!strcmp(s, ";")) { + arg->v[arg->c] = 0; + free(s); + s = 0; + } + last = s; + pl->count = -1; - arg[pl->count].v = xzalloc(sizeof(void *)); - *arg[pl->count].v = arg->v[++i]; - arg[pl->count].c = 0; - } + continue; + } else arg->v[++arg->c] = 0; - // function in progress? + // 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; @@ -560,7 +773,7 @@ static int parse_line(char *line, struct sh_parse *sp) if (strcmp(s, ")")) goto flush; // end function segment, expect function body - arg = 0; + pl->count = -1; last = 0; dlist_add(&sp->expect, "}"); dlist_add(&sp->expect, 0); @@ -575,8 +788,9 @@ static int parse_line(char *line, struct sh_parse *sp) // When waiting for { it must be next symbol, but can be on a new line. if (ex && !strcmp(ex, "{")) { - if (strcmp(s, "{") || (!i && *end)) goto flush; + if (strcmp(s, "{") || *end) goto flush; free(arg->v[--arg->c]); + free(dlist_lpop(&sp->expect)); continue; } @@ -592,7 +806,7 @@ static int parse_line(char *line, struct sh_parse *sp) // Expecting NULL means a statement: any otherwise unrecognized word else if (sp->expect && !ex) { - free(dlist_pop(&sp->expect)); + free(dlist_lpop(&sp->expect)); continue; } else if (!ex) goto check; @@ -600,17 +814,17 @@ static int parse_line(char *line, struct sh_parse *sp) pl->type = 1; // Only innermost statement needed in { { { echo ;} ;} ;} and such - if (sp->expect && !sp->expect->prev->data) free(dlist_pop(&sp->expect)); + 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(end, "&")) { + if (last && strcmp(last, "&")) { s = end; goto flush; } - free(dlist_pop(&sp->expect)); + free(dlist_lpop(&sp->expect)); pl->type = anyof(s, (char *[]){"fi", "done", "esac", "}", "]]", ")"}) ? 3 : 2; @@ -621,7 +835,7 @@ static int parse_line(char *line, struct sh_parse *sp) // fi could have elif, which queues a then. } else if (!strcmp(ex, "fi")) { if (!strcmp(s, "elif")) { - free(dlist_pop(&sp->expect)); + free(dlist_lpop(&sp->expect)); end = "then"; // catch duplicate else while we're here } else if (!strcmp(s, "else")) { @@ -629,7 +843,7 @@ static int parse_line(char *line, struct sh_parse *sp) s = "2 else"; goto flush; } - free(dlist_pop(&sp->expect)); + free(dlist_lpop(&sp->expect)); end = "fi\0B"; } } @@ -639,6 +853,7 @@ static int parse_line(char *line, struct sh_parse *sp) 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: @@ -646,6 +861,8 @@ check: if (!pl->type && anyof(s, (char *[]){"then", "do", "esac", "}", "]]", ")", "done", "then", "fi", "elif", "else"})) goto flush; } + + free(delete); if (0) if (sp->expect) { @@ -656,10 +873,14 @@ for (dl = sp->expect; dl; dl = (dl->next == sp->expect) ? 0 : dl->next) if (sp->pipeline) dprintf(2, "count=%d here=%d\n", sp->pipeline->prev->count, sp->pipeline->prev->here); } - // return if HERE document or more flow control + // 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 && sp->pipeline->prev->count != sp->pipeline->prev->here) - return 1; + if (sp->pipeline && pl->count != pl->here) return 1; // At this point, we've don't need more input and can start executing. @@ -669,7 +890,7 @@ struct sh_pipeline *ppl = pl; int q = 0; for (pl = sp->pipeline; pl ; pl = (pl->next == sp->pipeline) ? 0 : pl->next) { for (i = 0; i<pl->arg->c; i++) printf("arg[%d][%ld]=%s\n", q, i, pl->arg->v[i]); - printf("term[%d]=%s\n", q++, pl->arg->v[pl->arg->c]); + printf("type=%d term[%d]=%s\n", pl->type, q++, pl->arg->v[pl->arg->c]); } pl = ppl; } @@ -678,16 +899,68 @@ pl = ppl; // Now we have a complete thought and can start running stuff. - // iterate through the commands running each one + struct blockstack { + struct blockstack *next; + struct sh_pipeline *start, *now, *end; + int run, val, rdcount, redir[0]; + } *blk = 0, *new; + + // iterate through the commands + dlist_terminate(pl = sp->pipeline); + while (pl) { + s = *pl->arg->v; + + // Normal executable statement? + if (!pl->type) { + +// inherit redirects? +// returns last statement of pipeline + if (!blk) pl = run_pipeline(pl, 0, 0); + else if (blk->run) pl = run_pipeline(pl, blk->rdcount, blk->redir); + else do pl = pl->next; while (!pl->type); + + // Starting a new block? + } else if (pl->type == 1) { + struct sh_pipeline *end = block_end(pl); + + // If we're not running this, skip ahead. + if (blk && !blk->run) { + pl = end; + continue; + } - // run a pipeline of commands - for (pl = sp->pipeline; pl ; pl = (pl->next == sp->pipeline) ? 0 : pl->next) { - arg = pl->arg; + // If we are, save context and add it to the stack. + new = xzalloc(sizeof(*blk)); + new->next = blk; + blk = new; + blk->start = blk->now = pl; + blk->end = end; + blk->run = 1; -/* - function () { commands ; } - local variables in functions +// todo perform block end redirects + + } 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; + + // If ending a block, pop stack. + } else if (pl->type == 3) { + new = blk->next; + free(blk); + blk = new; + +// todo unwind redirects + + } else if (pl->type == 'f') { +dprintf(2, "skipped function definition %s\n", *pl->arg->v); +pl = block_end(pl); + } + + + +/* if/then/elif/else/fi for select while until/do/done case/esac @@ -695,10 +968,8 @@ case/esac [[/]] (/) function/} - */ - - run_command(arg); + pl = pl->next; } s = 0; |