diff options
| -rw-r--r-- | toys/pending/sh.c | 544 |
1 files changed, 364 insertions, 180 deletions
diff --git a/toys/pending/sh.c b/toys/pending/sh.c index 9f686932..7436ada2 100644 --- a/toys/pending/sh.c +++ b/toys/pending/sh.c @@ -8,7 +8,7 @@ * * The first link describes the following shell builtins: * - * break colon continue dot eval exec exit export readonly return set shift + * break : continue dot eval exec exit export readonly return set shift * times trap unset * * The second link (the utilities directory) also contains specs for the @@ -25,9 +25,9 @@ * TODO: Handle embedded NUL bytes in the command line? (When/how?) * TODO: replace getenv() with faster func: sort env and binary search - * buitins: alias bg command fc fg getopts jobs newgrp read umask unalias wait - * disown umask suspend source pushd popd dirs logout times trap - * unset local export readonly set : . let history declare + * builtins: alias bg command fc fg getopts jobs newgrp read umask unalias wait + * disown umask suspend source pushd popd dirs logout times trap + * unset local export readonly set : . let history declare * "special" builtins: break continue eval exec return shift * builtins with extra shell behavior: kill pwd time test @@ -121,10 +121,13 @@ GLOBALS( 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 + // undo redirects, a=b at start, child PID, exit status, has ! + int *urd, envlen, pid, exit, not; struct sh_arg arg; } *procs, *proc; } *jobs, *job; + + struct sh_arg *arg; ) #define BUGBUG 0 @@ -216,27 +219,35 @@ static char *getvar(char *s) return getvarlen(s, strlen(s)); } -// returns offset of next unquoted (or double quoted if dquot) char. -// handles \ '' "" `` $() -int skip_quote(char *s, int dquot, int *depth) +// TODO: make parse_word use this? +// returns length of current quote context. Handles \ '' "" `` $() +int skip_quote(char *s) { - int i, q = dquot ? *depth : 0; + int i, q = 0; // quotes were checked for balance and overflow by parse_word() for (i = 0; s[i]; i++) { char c = s[i], qq = q ? toybuf[q-1] : 0; - if (c == '\\') i++; - else if (dquot && q==1 && qq=='"' && c!='"') break; - else if (qq!='\'' && c=='$' && s[1]=='(') { + // backslash escapes skip a char, and return for EOL or unquoted. + if (c == '\\') { + if (qq!= '\'' && qq!='`') { + if (!s[++i]) return i; + if (!q) return ++i; + } + // $( triggers anywhere but inside ' ' + } else if (qq!='\'' && c=='$' && s[1]=='(') { toybuf[q++] = ')'; - i++; - } else if (q && qq==c) q--; + i+=2; + // unquoted parentheses nest inside $(), I.E. "$(()" isn't done yet. + } else if (c=='(' && qq==')') toybuf[q++] = ')'; + // end current quoting context with match + else if (q && qq==c) q--; + // start new non-nesting quoting context only at top level else if ((!q || qq==')') && (c=='"' || c=='\'' || c=='`')) toybuf[q++] = c; - else if (!q) break; - } - if (dquot) *depth = q; + if (!q) break; + } return i; } @@ -253,6 +264,213 @@ void add_arg(struct arg_list **list, char *arg) *list = al; } +// 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, "%d redir from=%d to=%d hfd=%d\n", getpid(), 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; +} + +// 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; +} + +// TODO check every caller of run_subshell for error, or syntax_error() here +// from pipe() failure + +// TODO eliminate prototypes +static int sh_run(char *new); +static void unredirect(int *urd); + + +// Pass environment and command string to child shell, return PID of child +static int run_subshell(char *str, int len) +{ + pid_t pid; + + // The with-mmu path is significantly faster. + if (CFG_TOYBOX_FORK) { + char *s; + + if ((pid = fork())<0) perror_msg("fork"); + else if (!pid) { + s = xstrndup(str, len); + sh_run(s); + free(s); + + _exit(toys.exitval); + } + + // On nommu vfork, exec /proc/self/exe, and pipe state data to ourselves. + } else { + int pipes[2], i; + + // open pipe to child + if (pipe(pipes) || 254 != dup2(pipes[0], 254)) return 1; + close(pipes[0]); + fcntl(pipes[1], F_SETFD, FD_CLOEXEC); + + // vfork child + pid = xpopen_setup(0, 0, subshell_callback); + + // marshall data to child + 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; +} + +// Call subshell with either stdin/stdout redirected, return other end of pipe +int pipe_subshell(char *s, int len, int out) +{ + int pipes[2], *uu = 0, in = !out; + + // Grab subshell data + if (pipe(pipes)) { + perror_msg("%.*s", len, s); + + return -1; + } + + // Perform input or output redirect and launch process + save_redirect(&uu, pipes[in], in); + close(pipes[in]); + run_subshell(s, len); // ignore errors, don't track + unredirect(uu); + + return pipes[out]; +} + +// utf8 strchr: return wide char matched at wc from chrs, or 0 if not matched +// if len, save length of wc when matched +static int utf8chr(char *wc, char *chrs, int *len) +{ + wchar_t wc1, wc2; + int ll; + + if (!*wc) return 0; + + ll = utf8towc(&wc1, wc, 99); + if (ll<0 || wc1<1) { + if (len) ++*len; + return *wc; + } + if (wc1 > 0) { + if (len) *len = ll; + while (*(chrs += utf8towc(&wc2, chrs, 99))) if (wc1 == wc2) break; + if (*chrs) return wc1; + } + + return 0; +} + +// find utf8 characters in utf string +// if c return first char in chrs or null terminator (ala strcspn) +// else return first char not in chars (ala strspn) +static char *utf8spnc(char *str, char *chrs, int c) +{ + int ll, len; + + while (*str) { + ll = utf8chr(str, chrs, &len); + if (c ? ll : !ll) break; + str += len; + } + + return str; +} + + +// This reeeeeally wants to be inline because we marshall half the function's +// state to it and it write _back_ to more than one. End of loop? + +// Perform word splitting via $IFS, adding split chunks +// Returns newly allocated end chunk. +// input *off is length of new, output *off = resolved length +static char *split_add(struct sh_arg *arg, struct arg_list **delete, + char *before, char *new, char *after, char quote, int *off) +{ +// TODO TT.ifs + char *ifs = getenv("IFS"), *end = new; + int i, j, len; + + if (!ifs) ifs = " \t\n"; + + if (!(quote&1)) while (*new && *(end = utf8spnc(new, ifs, 1))) { + new = xmprintf("%.*s%.*s", *off, before, (int)(end-new), new); + *off = 0; + for (j = 0; (i = utf8chr(end, ifs, &len)); end += len) { + + // runs of space allowed/collapsed before and after non-whitespace IFS + if (!(j&1)) { + if (iswspace(i)) { + if (!j && new && !*new && !quote) { + free(new); + new = 0; + } + } else if (++j == 3) break; + } else j++; + } + if (new) { + add_arg(delete, new); + array_add(&arg->v, arg->c++, new); + quote = 0; + } + new = end; + } + + end = xmprintf("%.*s%s%s", *off, before, new, after); + *off += strlen(new); + + return end; +} + #define NO_PATH (1<<0) // path expansion (wildcards) #define NO_SPLIT (1<<1) // word splitting #define NO_BRACE (1<<2) // {brace,expansion} @@ -264,96 +482,158 @@ void add_arg(struct arg_list **list, char *arg) // 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 +// str = 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, +static void expand_arg_nobrace(struct sh_arg *arg, char *str, unsigned flags, struct arg_list **delete) { - char *new = old, *s, *ss, *sss; + char cc, qq = 0, *old = str, *new = str, *s, *ss; + int ii = 0, jj, kk, oo; if (flags&FORCE_KEEP) old = 0; // TODO ls -l /proc/$$/fd // Tilde expansion - if (!(flags&NO_TILDE) && *new == '~') { + if (!(flags&NO_TILDE) && *str == '~') { struct passwd *pw = 0; // first expansion so don't need to free previous new ss = 0; - for (s = new; *s && *s!=':' && *s!='/'; s++); - if (s-new==1) { + while (str[ii] && str[ii]!=':' && str[ii]!='/') s++; + if (ii==1) { if (!(ss = getvar("HOME")) || !*ss) pw = bufgetpwuid(getuid()); } else { // TODO bufgetpwnam - pw = getpwnam(sss = xstrndup(new+1, (s-new)-1)); - free(sss); + pw = getpwnam(s = xstrndup(str+1, ii-1)); + free(s); } if (pw && pw->pw_dir) ss = pw->pw_dir; if (!ss || !*ss) ss = "/"; - s = xmprintf("%s%s", ss, s); + s = xmprintf("%s%s", ss, str+ii); if (old != new) free(new); new = s; } - // parameter/variable expansion + // parameter/variable expansion, and dequoting -// TODO this is wrong - if (*new == '$') { - char *s = getvar(new+1); + for (oo = 0; (cc = str[ii++]); old != new && (new[oo] = 0)) { + // skip literal chars + if (!strchr("$'`\\\"", cc)) { + if (old != new) new[oo++] = cc; + continue; + } - if (new != old) free(new); - if (!s) return; - new = xstrdup(s); - } + // allocate snapshot if we just started modifying + if (old == new) { + new = xstrdup(new); + new[oo = ii-1] = 0; + } -/* - for (s = new; *(s += skip_quote(s, 1, &depth));) { - if (*s == '`') { + // handle different types of escapes + if (cc == '\\') new[oo++] = str[ii] ? str[ii++] : cc; + else if (cc == '"') qq++; + else if (cc == '\'') { + if (qq&1) new[oo++] = cc; + else { + qq += 2; + while ((cc = str[ii++]) != '\'') new[oo++] = cc; + } + // both types of subshell work the same, so do $( here not in '$' below +// TODO $((echo hello) | cat) ala $(( becomes $( ( retroactively + } else if (cc == '`' || (cc == '$' && str[ii] == '(' && str[ii+1] != '(')) { + kk = skip_quote(str+ii); + jj = cc == '$'; +// TODO what does \ in `` mean? What is echo `printf %s \$x` supposed to do? + jj = pipe_subshell(str+ii+1+jj, kk-2-jj, 1); + ii += kk; + ss = readfd(jj, 0, 0); + close(jj); + if (ss && *ss) { + kk = strlen(ss); + while (kk && ss[kk-1]=='\n') ss[--kk] = 0; + + s = split_add(arg, delete, new, ss, str+ii, qq, &oo); + if (new != old) free(new); + new = s; + } + // Blank subshells don't add an argument. + if (!str[ii]) { + if (new != old) free(new); + new = 0; + } + } else if (cc == '$') { + char buf[16]; + s = buf; + +// *@#?-$!_0 "Special Paremeters" ($0 not affected by shift) + + + if (!(cc = str[ii++])) { + new[oo++] = cc; + break; + } else if (cc == '?') { + char buf[16]; + sprintf(buf, "%d", toys.exitval); + + s = split_add(arg, delete, new, buf, str+ii, qq, &oo); + if (new != old) free(new); + new = s; + } else if (cc == '*' || cc == '@') { + // Quoted agglomeration + if ((qq&1) && cc=='*') { + for (jj = kk = 0; jj<TT.arg->c; jj++) kk += strlen(TT.arg->v[jj]); + s = xmalloc(oo+kk+TT.arg->c+strlen(str+ii)+1); + memcpy(s, new, oo); + for (jj = 0; jj<TT.arg->c; jj++) + oo += sprintf(s+oo, " %s"+!jj, TT.arg->v[jj]); + strcpy(s+oo, str+ii); + } else for (jj = 0; jj<TT.arg->c; jj++) { + s = split_add(arg, delete, new, TT.arg->v[jj], + jj+1==TT.arg->c ? str+ii : "", qq, &oo); + if (new != old) free(new); + new = s; + } + } else if(isdigit(cc)) { + for (kk = 0, ii--; isdigit(cc = str[ii]); ii++) kk = (10*kk)+cc-'0'; + s = split_add(arg, delete, new, kk<TT.arg->c ? TT.arg->v[kk] : "", + str+ii, qq, &oo); + if (new != old) free(new); + new = s; -// ${ $(( $( $[ $' ` " ' + // TODO: ${ $(( $( $[ $' +// } else if (cc == '{') { - while (*s) { - if (quote != '*s == '$') { - // *@#?-$!_0 "Special Paremeters" ($0 not affected by shift) - // 0-9 positional parameters - if (s[1] == '$' + } else { + s = str+--ii; + for (jj = 0; s[jj] && (s[jj]=='_' || !ispunct(s[jj])); jj++); + s = jj ? getvarlen(str+ii, jj) : 0; + s = xstrdup(s ? s : ""); + ii += jj; + s = split_add(arg, delete, new, s, str+ii, qq, &oo); + if (new != old) free(new); + new = s; + } } } - // replacement - while (*s) { - if (*s == '$') { - s++; - } else if (*strchr("*?[{", *s)) { - s++; - } else if (*s == '<' || *s == '>') { - s++; - } else s++; - } -*/ +// TODO globbing * ? [ -// TODO not else? - // quote removal - else if (!(flags&NO_QUOTE)) { - int to = 0, from = 0; +// Word splitting completely eliminating argument when no non-$IFS data left +// wordexp keeps pattern when no matches - for (;;) { - char c = new[from++]; +// TODO NO_SPLIT cares about IFS, see also trailing \n - if (c == '"' || c=='\'') continue; - if (c == '\\' && new[from]) c = new[from++]; - if (from != to && old == new) new = xstrdup(new); - if (!(new[to++] = c)) break; - } - } +// quote removal // 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); + if (*new || qq) { + if (old==new && (flags&FORCE_COPY)) new = xstrdup(new); + if (old!=new) add_arg(delete, new); + array_add(&arg->v, arg->c++, new); + } else if(old != new) free(new); } // expand braces (ala {a,b,c}) and call expand_arg_nobrace() each permutation @@ -369,7 +649,7 @@ static void expand_arg(struct sh_arg *arg, char *old, unsigned flags, // collect brace spans if (!(flags&NO_BRACE)) for (i = 0; ; i++) { - i += skip_quote(old+i, 0, 0); + while ((j = skip_quote(old+i))) i += j; if (!bb && !old[i]) break; if (bb && (!old[i] || old[i] == '}')) { bb->active = bb->commas[bb->cnt+1] = i; @@ -552,51 +832,6 @@ if (BUGBUG) dprintf(255, "urd %d %d\n", rr[0], rr[1]); 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, "%d redir from=%d to=%d hfd=%d\n", getpid(), 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; @@ -615,59 +850,6 @@ struct sh_function { char *end; }; -// 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; -} - -// TODO avoid prototype -static int sh_run(char *new); - -// Pass environment and command string to child shell, return PID of child -static int run_subshell(char *str, int len) -{ - pid_t pid; - - // The with-mmu path is significantly faster. - if (CFG_TOYBOX_FORK) { - char *s; - - if ((pid = fork())<0) perror_msg("fork"); - else if (!pid) { - s = xstrndup(str, len); - sh_run(s); - free(s); - - _exit(toys.exitval); - } - - // On nommu vfork, exec /proc/self/exe, and pipe state data to ourselves. - } else { - int pipes[2], i; - - // open pipe to child - if (pipe(pipes) || 254 != dup2(pipes[0], 254)) return 1; - close(pipes[0]); - fcntl(pipes[1], F_SETFD, FD_CLOEXEC); - - // vfork child - pid = xpopen_setup(0, 0, subshell_callback); - - // marshall data to child - 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; -} - // turn a parsed pipeline back into a string. static char *pl2str(struct sh_pipeline *pl) { @@ -718,27 +900,19 @@ static struct sh_process *expand_redir(struct sh_arg *arg, int envlen, int *urd) // Handle <() >() redirectionss if ((*s == '<' || *s == '>') && s[1] == '(') { - int pipes[2], *uu = 0, dd; + int new = pipe_subshell(s+2, strlen(s+1)-1, *s == '>'); // Grab subshell data - if (pipe(pipes)) { - perror_msg_raw(s); + if (new == -1) { 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]); + save_redirect(&urd, -1, new); // 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])); + add_arg(&pp->delete, ss = xmprintf("/proc/self/fd/%d", new)); array_add(&pp->arg.v, pp->arg.c++, ss); continue; @@ -1887,6 +2061,7 @@ void subshell_setup(void) { struct passwd *pw = getpwuid(getuid()); int to, from, pid = 0, ppid = 0, mypid, myppid, len; +// TODO: you can unset readonly and these first 4 aren't malloc() char *s, *ss, **ll, *locals[] = {"GROUPS=", "SECONDS=", "RANDOM=", "LINENO=", xmprintf("PPID=%d", myppid = getppid()), xmprintf("EUID=%d", geteuid()), xmprintf("$=%d", mypid = getpid()), xmprintf("UID=%d", getuid())}; @@ -1982,10 +2157,19 @@ void sh_main(void) char *new; struct sh_function scratch; int prompt = 0; + struct sh_arg arg; TT.hfd = 10; signal(SIGPIPE, SIG_IGN); + TT.arg = &arg; + if (!(arg.c = toys.optc)) { + arg.v = xmalloc(2*sizeof(char *)); + arg.v[arg.c++] = *toys.argv; + arg.v[arg.c] = 0; + } else memcpy(arg.v = xmalloc((arg.c+1)*sizeof(char *)), toys.optargs, + (arg.c+1)*sizeof(char *)); + // TODO euid stuff? // TODO login shell? // TODO read profile, read rc |