From 6fbb43bc3c14fc30030cae77db51c322bece30ab Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 24 Jul 2008 19:44:41 +0000 Subject: ash: teach ash about 123>file. It could take only 0..9 before function old new delta redirect 1052 1139 +87 need_to_remember - 36 +36 popredir 132 148 +16 fixredir 86 101 +15 readtoken1 3130 3143 +13 evalvar 1374 1376 +2 popstring 140 134 -6 cmdtxt 592 561 -31 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 5/2 up/down: 169/-37) Total: 132 bytes --- shell/ash.c | 142 +++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 97 insertions(+), 45 deletions(-) diff --git a/shell/ash.c b/shell/ash.c index 6de71f6..22575ff 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -62,6 +62,10 @@ #include #endif +#ifndef PIPE_BUF +#define PIPE_BUF 4096 /* amount of buffering in a pipe */ +#endif + #if defined(__uClinux__) #error "Do not even bother, ash will not run on uClinux" #endif @@ -4285,7 +4289,6 @@ cmdtxt(union node *n) union node *np; struct nodelist *lp; const char *p; - char s[2]; if (!n) return; @@ -4417,14 +4420,11 @@ cmdtxt(union node *n) case NFROMTO: p = "<>"; redir: - s[0] = n->nfile.fd + '0'; - s[1] = '\0'; - cmdputs(s); + cmdputs(utoa(n->nfile.fd)); cmdputs(p); if (n->type == NTOFD || n->type == NFROMFD) { - s[0] = n->ndup.dupfd + '0'; - p = s; - goto dotail2; + cmdputs(utoa(n->ndup.dupfd)); + break; } n = n->nfile.fname; goto donode; @@ -4675,11 +4675,6 @@ stoppedjobs(void) #define EMPTY -2 /* marks an unused slot in redirtab */ #define CLOSED -3 /* marks a slot of previously-closed fd */ -#ifndef PIPE_BUF -# define PIPESIZE 4096 /* amount of buffering in a pipe */ -#else -# define PIPESIZE PIPE_BUF -#endif /* * Open a file in noclobber mode. @@ -4756,7 +4751,7 @@ openhere(union node *redir) ash_msg_and_raise_error("pipe call failed"); if (redir->type == NHERE) { len = strlen(redir->nhere.doc->narg.text); - if (len <= PIPESIZE) { + if (len <= PIPE_BUF) { full_write(pip[1], redir->nhere.doc->narg.text, len); goto out; } @@ -4860,19 +4855,40 @@ copyfd(int from, int to) if (newfd < 0) { if (errno == EMFILE) return EMPTY; + /* Happens when source fd is not open: try "echo >&99" */ ash_msg_and_raise_error("%d: %m", from); } return newfd; } /* Struct def and variable are moved down to the first usage site */ +struct two_fd_t { + int orig, copy; +}; struct redirtab { struct redirtab *next; - int renamed[10]; int nullredirs; + int pair_count; + struct two_fd_t two_fd[0]; }; #define redirlist (G_var.redirlist) +static int need_to_remember(struct redirtab *rp, int fd) +{ + int i; + + if (!rp) /* remebering was not requested */ + return 0; + + for (i = 0; i < rp->pair_count; i++) { + if (rp->two_fd[i].orig == fd) { + /* already remembered */ + return 0; + } + } + return 1; +} + /* * Process a list of redirection commands. If the REDIR_PUSH flag is set, * old file descriptors are stashed away so that the redirection can be @@ -4887,24 +4903,36 @@ static void redirect(union node *redir, int flags) { struct redirtab *sv; + int sv_pos; int i; int fd; int newfd; + int copied_fd2 = -1; g_nullredirs++; if (!redir) { return; } + sv = NULL; + sv_pos = 0; INT_OFF; if (flags & REDIR_PUSH) { - sv = ckmalloc(sizeof(*sv)); + union node *tmp = redir; + do { + sv_pos++; + tmp = tmp->nfile.next; + } while (tmp); + sv = ckmalloc(sizeof(*sv) + sv_pos * sizeof(sv->two_fd[0])); sv->next = redirlist; + sv->pair_count = sv_pos; redirlist = sv; sv->nullredirs = g_nullredirs - 1; g_nullredirs = 0; - for (i = 0; i < 10; i++) - sv->renamed[i] = EMPTY; + while (sv_pos > 0) { + sv_pos--; + sv->two_fd[sv_pos].orig = sv->two_fd[sv_pos].copy = EMPTY; + } } do { @@ -4918,19 +4946,25 @@ redirect(union node *redir, int flags) if (fd == newfd) { /* Descriptor wasn't open before redirect. * Mark it for close in the future */ - if (sv && sv->renamed[fd] == EMPTY) - sv->renamed[fd] = CLOSED; + if (need_to_remember(sv, fd)) { + if (fd == 2) + copied_fd2 = CLOSED; /// do we need this? + sv->two_fd[sv_pos].orig = fd; + sv->two_fd[sv_pos].copy = CLOSED; + sv_pos++; + } continue; } } - if (sv && sv->renamed[fd] == EMPTY) { + if (need_to_remember(sv, fd)) { /* Copy old descriptor */ i = fcntl(fd, F_DUPFD, 10); if (i == -1) { i = errno; if (i != EBADF) { /* Strange error (e.g. "too many files" EMFILE?) */ - /*if (newfd >= 0)*/ close(newfd); + if (newfd >= 0) + close(newfd); errno = i; ash_msg_and_raise_error("%d: %m", fd); /* NOTREACHED */ @@ -4938,10 +4972,15 @@ redirect(union node *redir, int flags) /* EBADF: it is not open - ok */ } else { /* fd is open, save its copy */ -//TODO: CLOEXEC the copy? currently these extra "saved" fds are closed -// in popredir() in the child, preventing them from leaking into child. -// (popredir() also cleans up the mess in case of failures) - sv->renamed[fd] = i; +/* You'd expect copy to be CLOEXECed. Currently these extra "saved" fds + * are closed in popredir() in the child, preventing them from leaking + * into child. (popredir() also cleans up the mess in case of failures) + */ + if (fd == 2) + copied_fd2 = i; + sv->two_fd[sv_pos].orig = fd; + sv->two_fd[sv_pos].copy = i; + sv_pos++; close(fd); } } else { @@ -4960,8 +4999,8 @@ redirect(union node *redir, int flags) } while ((redir = redir->nfile.next) != NULL); INT_ON; - if ((flags & REDIR_SAVEFD2) && sv && sv->renamed[2] >= 0) - preverrout_fd = sv->renamed[2]; + if ((flags & REDIR_SAVEFD2) && copied_fd2 >= 0) + preverrout_fd = copied_fd2; } /* @@ -4977,18 +5016,19 @@ popredir(int drop) return; INT_OFF; rp = redirlist; - for (i = 0; i < 10; i++) { - if (rp->renamed[i] == CLOSED) { + for (i = 0; i < rp->pair_count; i++) { + int fd = rp->two_fd[i].orig; + if (rp->two_fd[i].copy == CLOSED) { if (!drop) - close(i); + close(fd); continue; } - if (rp->renamed[i] != EMPTY) { + if (rp->two_fd[i].copy != EMPTY) { if (!drop) { - close(i); - copyfd(rp->renamed[i], i); + close(fd); + copyfd(rp->two_fd[i].copy, fd); } - close(rp->renamed[i]); + close(rp->two_fd[i].copy); } } redirlist = rp->next; @@ -10003,12 +10043,15 @@ makename(void) static void fixredir(union node *n, const char *text, int err) { + int fd; + TRACE(("Fix redir %s %d\n", text, err)); if (!err) n->ndup.vname = NULL; - if (isdigit(text[0]) && text[1] == '\0') - n->ndup.dupfd = text[0] - '0'; + fd = bb_strtou(text, NULL, 10); + if (!errno && fd >= 0) + n->ndup.dupfd = fd; else if (LONE_DASH(text)) n->ndup.dupfd = -1; else { @@ -10630,7 +10673,7 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs) } c = pgetc_macro(); - } /* for(;;) */ + } /* for (;;) */ } endword: #if ENABLE_ASH_MATH_SUPPORT @@ -10650,12 +10693,20 @@ readtoken1(int firstc, int syntax, char *eofmark, int striptabs) if (eofmark == NULL) { if ((c == '>' || c == '<') && quotef == 0 - && len <= 2 // THIS LIMITS fd to 1 char: N>file, but no NN>file! - && (*out == '\0' || isdigit(*out)) + // && len <= 2 // THIS LIMITS fd to 1 char: N>file, but no NN>file! + // && (*out == '\0' || isdigit(*out)) ) { - PARSEREDIR(); - lasttoken = TREDIR; - return lasttoken; + int maxlen = 9 + 1; /* max 9 digit fd#: 999999999 */ + char *np = out; + while (--maxlen && isdigit(*np)) + np++; + if (*np == '\0') { + PARSEREDIR(); /* passed as params: out, c */ + lasttoken = TREDIR; + return lasttoken; + } + /* else: non-number X seen, interpret it + * as "NNNX>file" = "NNNX >file" */ } pungetc(); } @@ -10710,7 +10761,8 @@ checkend: { * first character of the redirection operator. */ parseredir: { - char fd = *out; + /* out is already checked to be a valid number or "" */ + int fd = (*out == '\0' ? -1 : atoi(out)); union node *np; np = stzalloc(sizeof(struct nfile)); @@ -10762,8 +10814,8 @@ parseredir: { break; } } - if (fd != '\0') - np->nfile.fd = fd - '0'; + if (fd >= 0) + np->nfile.fd = fd; redirnode = np; goto parseredir_return; } -- cgit v1.1