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Diffstat (limited to 'src/kash/redir.c')
| -rw-r--r-- | src/kash/redir.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/src/kash/redir.c b/src/kash/redir.c new file mode 100644 index 0000000..e9c3092 --- /dev/null +++ b/src/kash/redir.c @@ -0,0 +1,484 @@ +/* $NetBSD: redir.c,v 1.29 2004/07/08 03:57:33 christos Exp $ */ + +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if 0 +#ifndef lint +static char sccsid[] = "@(#)redir.c 8.2 (Berkeley) 5/4/95"; +#else +__RCSID("$NetBSD: redir.c,v 1.29 2004/07/08 03:57:33 christos Exp $"); +#endif /* not lint */ +#endif + +#include <sys/types.h> +#include <limits.h> /* PIPE_BUF */ +#include <string.h> +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> + +/* + * Code for dealing with input/output redirection. + */ + +#include "main.h" +#include "shell.h" +#include "nodes.h" +#include "jobs.h" +#include "options.h" +#include "expand.h" +#include "redir.h" +#include "output.h" +#include "memalloc.h" +#include "error.h" +#include "shinstance.h" + + +#define EMPTY -2 /* marks an unused slot in redirtab */ +#define PIPESIZE SHFILE_PIPE_SIZE + + +//MKINIT struct redirtab *redirlist; + +/* + * We keep track of whether or not fd0 has been redirected. This is for + * background commands, where we want to redirect fd0 to /dev/null only + * if it hasn't already been redirected. +*/ +//int fd0_redirected = 0; + +STATIC void openredirect(shinstance *, union node *, char[10], int, const char *); +STATIC int openhere(shinstance *, union node *); + + +#ifndef SH_FORKED_MODE +void +subshellinitredir(shinstance *psh, shinstance *inherit) +{ + /* We can have a redirlist here if we're handling backtick while expanding + arguments, just copy it even if the subshell probably doesn't need it. */ + struct redirtab *src = inherit->redirlist; + if (src) + { + struct redirtab **dstp = &psh->redirlist; + do + { + struct redirtab *dst = ckmalloc(psh, sizeof(*dst)); + memcpy(dst->renamed, src->renamed, sizeof(dst->renamed)); + *dstp = dst; + dstp = &dst->next; + src = src->next; + } while (src); + *dstp = NULL; + + psh->fd0_redirected = inherit->fd0_redirected; + } + + /* Copy the expanded redirection filenames (stack), but only the last entry + as the subshell does not have the ability to unwind stack in the parent + and therefore cannot get to the earlier redirection stuff: */ + if (inherit->expfnames) + { + redirexpfnames * const expfnamesrc = inherit->expfnames; + unsigned i = expfnamesrc->count; + redirexpfnames *dst = stalloc(psh, offsetof(redirexpfnames, names) + sizeof(dst->names[0]) * i); + dst->count = i; + dst->depth = 1; + dst->prev = NULL; + while (i-- > 0) + dst->names[i] = stsavestr(psh, expfnamesrc->names[i]); + psh->expfnames = dst; + } +} +#endif /* !SH_FORKED_MODE */ + + +/* + * 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 + * undone by calling popredir. If the REDIR_BACKQ flag is set, then the + * standard output, and the standard error if it becomes a duplicate of + * stdout, is saved in memory. + */ + +void +redirect(shinstance *psh, union node *redir, int flags) +{ + union node *n; + struct redirtab *sv = NULL; + int i; + int fd; + int try; + char memory[10]; /* file descriptors to write to memory */ + unsigned idxexpfname; + + for (i = 10 ; --i >= 0 ; ) + memory[i] = 0; + memory[1] = flags & REDIR_BACKQ; + if (flags & REDIR_PUSH) { + sv = ckmalloc(psh, sizeof (struct redirtab)); + for (i = 0 ; i < 10 ; i++) + sv->renamed[i] = EMPTY; + sv->next = psh->redirlist; + psh->redirlist = sv; + } + idxexpfname = 0; + for (n = redir, idxexpfname = 0 ; n ; n = n->nfile.next, idxexpfname++) { + kHlpAssert(idxexpfname < psh->expfnames->count); + fd = n->nfile.fd; + try = 0; + if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) && + n->ndup.dupfd == fd) + continue; /* redirect from/to same file descriptor */ + + if ((flags & REDIR_PUSH) && sv->renamed[fd] == EMPTY) { + INTOFF; +again: + if ((i = shfile_fcntl(&psh->fdtab, fd, F_DUPFD, 10)) == -1) { + switch (errno) { + case EBADF: + if (!try) { + openredirect(psh, n, memory, flags, psh->expfnames->names[idxexpfname]); + try++; + goto again; + } + /* FALLTHROUGH*/ + default: + INTON; + error(psh, "%d: %s", fd, sh_strerror(psh, errno)); + /* NOTREACHED */ + } + } + if (!try) { + sv->renamed[fd] = i; + shfile_close(&psh->fdtab, fd); + } + INTON; + } else { + shfile_close(&psh->fdtab, fd); + } + if (fd == 0) + psh->fd0_redirected++; + if (!try) + openredirect(psh, n, memory, flags, psh->expfnames->names[idxexpfname]); + } + kHlpAssert(!redir || idxexpfname == psh->expfnames->count); + if (memory[1]) + psh->out1 = &psh->memout; + if (memory[2]) + psh->out2 = &psh->memout; +} + + +STATIC void +openredirect(shinstance *psh, union node *redir, char memory[10], int flags, const char *fname) +{ + int fd = redir->nfile.fd; + int f; + int oflags = O_WRONLY|O_CREAT|O_TRUNC; + + /* + * We suppress interrupts so that we won't leave open file + * descriptors around. This may not be such a good idea because + * an open of a device or a fifo can block indefinitely. + */ + INTOFF; + memory[fd] = 0; + switch (redir->nfile.type) { + case NFROM: + if ((f = shfile_open(&psh->fdtab, fname, O_RDONLY, 0)) < 0) + goto eopen; + break; + case NFROMTO: + if ((f = shfile_open(&psh->fdtab, fname, O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0) + goto ecreate; + break; + case NTO: + if (Cflag(psh)) + oflags |= O_EXCL; + /* FALLTHROUGH */ + case NCLOBBER: + if ((f = shfile_open(&psh->fdtab, fname, oflags, 0666)) < 0) + goto ecreate; + break; + case NAPPEND: + if ((f = shfile_open(&psh->fdtab, fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0) + goto ecreate; + break; + case NTOFD: + case NFROMFD: + if (redir->ndup.dupfd >= 0) { /* if not ">&-" */ + if (memory[redir->ndup.dupfd]) + memory[fd] = 1; + else + copyfd(psh, redir->ndup.dupfd, fd); + } + INTON; + return; + case NHERE: + case NXHERE: + f = openhere(psh, redir); + break; + default: + sh_abort(psh); + } + + if (f != fd) { + movefd(psh, f, fd); + } + INTON; + return; +ecreate: + error(psh, "cannot create %s: %s", fname, errmsg(psh, errno, E_CREAT)); +eopen: + error(psh, "cannot open %s: %s", fname, errmsg(psh, errno, E_OPEN)); +} + +#ifdef KASH_USE_FORKSHELL2 +struct openherechild +{ + int pip[2]; + size_t len; +}; +static int openhere_child(shinstance *psh, union node *n, void *argp) +{ + struct openherechild args = *(struct openherechild *)argp; + + shfile_close(&psh->fdtab, args.pip[0]); + sh_signal(psh, SIGINT, SH_SIG_IGN); + sh_signal(psh, SIGQUIT, SH_SIG_IGN); + sh_signal(psh, SIGHUP, SH_SIG_IGN); +# ifdef SIGTSTP + sh_signal(psh, SIGTSTP, SH_SIG_IGN); +# endif + sh_signal(psh, SIGPIPE, SH_SIG_DFL); + if (n->type == NHERE) + xwrite(psh, args.pip[1], n->nhere.doc->narg.text, args.len); + else + expandhere(psh, n->nhere.doc, args.pip[1]); + return 0; +} + +#endif /* KASH_USE_FORKSHELL2*/ + +/* + * Handle here documents. Normally we fork off a process to write the + * data to a pipe. If the document is short, we can stuff the data in + * the pipe without forking. + */ + +STATIC int +openhere(shinstance *psh, union node *redir) +{ + int pip[2]; + size_t len = 0; + + if (shfile_pipe(&psh->fdtab, pip) < 0) + error(psh, "Pipe call failed"); + if (redir->type == NHERE) { + len = strlen(redir->nhere.doc->narg.text); + if (len <= PIPESIZE) { + xwrite(psh, pip[1], redir->nhere.doc->narg.text, len); + goto out; + } + } +#ifdef KASH_USE_FORKSHELL2 + { + struct openherechild args; + args.pip[0] = pip[0]; + args.pip[1] = pip[1]; + args.len = len; + forkshell2(psh, (struct job *)NULL, redir, + FORK_NOJOB | FORK_JUST_IO, + openhere_child, redir, &args, sizeof(args), NULL); + } +#else + if (forkshell(psh, (struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { + shfile_close(&psh->fdtab, pip[0]); + sh_signal(psh, SIGINT, SH_SIG_IGN); + sh_signal(psh, SIGQUIT, SH_SIG_IGN); + sh_signal(psh, SIGHUP, SH_SIG_IGN); +#ifdef SIGTSTP + sh_signal(psh, SIGTSTP, SH_SIG_IGN); +#endif + sh_signal(psh, SIGPIPE, SH_SIG_DFL); + if (redir->type == NHERE) + xwrite(psh, pip[1], redir->nhere.doc->narg.text, len); + else + expandhere(psh, redir->nhere.doc, pip[1]); + sh__exit(psh, 0); + } +#endif +out: + shfile_close(&psh->fdtab, pip[1]); + return pip[0]; +} + + + +/* + * Undo the effects of the last redirection. + */ + +void +popredir(shinstance *psh) +{ + struct redirtab *rp = psh->redirlist; + int i; + + for (i = 0 ; i < 10 ; i++) { + if (rp->renamed[i] != EMPTY) { + if (i == 0) + psh->fd0_redirected--; + if (rp->renamed[i] >= 0) { + movefd(psh, rp->renamed[i], i); + } else { + shfile_close(&psh->fdtab, i); + } + } + } + INTOFF; + psh->redirlist = rp->next; + ckfree(psh, rp); + INTON; +} + +/* + * Undo all redirections. Called on error or interrupt. + */ + +#ifdef mkinit + +INCLUDE "redir.h" + +RESET { + while (psh->redirlist) + popredir(psh); +} + +SHELLPROC { + clearredir(psh); +} + +#endif + +/* Return true if fd 0 has already been redirected at least once. */ +int +fd0_redirected_p(shinstance *psh) { + return psh->fd0_redirected != 0; +} + +/* + * Discard all saved file descriptors. + */ + +void +clearredir(shinstance *psh) +{ + struct redirtab *rp; + int i; + + for (rp = psh->redirlist ; rp ; rp = rp->next) { + for (i = 0 ; i < 10 ; i++) { + if (rp->renamed[i] >= 0) { + shfile_close(&psh->fdtab, rp->renamed[i]); + } + rp->renamed[i] = EMPTY; + } + } +} + + + +/* + * Copy a file descriptor to be >= to. Returns -1 + * if the source file descriptor is closed, EMPTY if there are no unused + * file descriptors left. + */ + +int +copyfd(shinstance *psh, int from, int to) +{ + int newfd; + + newfd = shfile_fcntl(&psh->fdtab, from, F_DUPFD, to); + if (newfd < 0) { + if (errno == EMFILE) + return EMPTY; + error(psh, "%d: %s", from, sh_strerror(psh, errno)); + } + return newfd; +} + + +/* + * Move a file descriptor to be == to. Returns -1 + * if the source file descriptor is closed, EMPTY if there are no unused + * file descriptors left. + */ + +int +movefd(shinstance *psh, int from, int to) +{ + int newfd; + + newfd = shfile_movefd(&psh->fdtab, from, to); + if (newfd < 0) { + if (errno == EMFILE) + return EMPTY; + error(psh, "%d: %s", from, sh_strerror(psh, errno)); + } + return newfd; +} + + +/* + * Move a file descriptor to be >= to. Returns -1 + * if the source file descriptor is closed, EMPTY if there are no unused + * file descriptors left. + */ + +int +movefd_above(shinstance *psh, int from, int to) +{ + int newfd; + + newfd = shfile_movefd_above(&psh->fdtab, from, to); + if (newfd < 0) { + if (errno == EMFILE) + return EMPTY; + error(psh, "%d: %s", from, sh_strerror(psh, errno)); + } + return newfd; +} + |