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Diffstat (limited to '')
| -rw-r--r-- | src/redir.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/src/redir.c b/src/redir.c new file mode 100644 index 0000000..9bebcb6 --- /dev/null +++ b/src/redir.c @@ -0,0 +1,488 @@ +/* $NetBSD: redir.c,v 1.27 2002/11/24 22:35:42 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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. + */ + +#include <sys/cdefs.h> +#ifndef lint +#if 0 +static char sccsid[] = "@(#)redir.c 8.2 (Berkeley) 5/4/95"; +#else +__RCSID("$NetBSD: redir.c,v 1.27 2002/11/24 22:35:42 christos Exp $"); +#endif +#endif /* not lint */ + +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/param.h> /* PIPE_BUF */ +#include <signal.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.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" + + +#define EMPTY -2 /* marks an unused slot in redirtab */ +#ifndef PIPE_BUF +# define PIPESIZE 4096 /* amount of buffering in a pipe */ +#else +# define PIPESIZE PIPE_BUF +#endif + + +MKINIT +struct redirtab { + struct redirtab *next; + int renamed[10]; + int nullredirs; +}; + + +MKINIT struct redirtab *redirlist; +MKINIT int nullredirs; + +STATIC int openredirect(union node *); +#ifdef notyet +STATIC void dupredirect(union node *, int, char[10]); +#else +STATIC void dupredirect(union node *, int); +#endif +STATIC int openhere(union node *); +STATIC int noclobberopen(const char *); + + +/* + * 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(union node *redir, int flags) +{ + union node *n; + struct redirtab *sv; + int i; + int fd; + int newfd; + int *p; +#if notyet + char memory[10]; /* file descriptors to write to memory */ + + for (i = 10 ; --i >= 0 ; ) + memory[i] = 0; + memory[1] = flags & REDIR_BACKQ; +#endif + nullredirs++; + if (!redir) { + return; + } + sv = NULL; + INTOFF; + if (flags & REDIR_PUSH) { + struct redirtab *q; + q = ckmalloc(sizeof (struct redirtab)); + q->next = redirlist; + redirlist = q; + q->nullredirs = nullredirs - 1; + for (i = 0 ; i < 10 ; i++) + q->renamed[i] = EMPTY; + nullredirs = 0; + sv = q; + } + n = redir; + do { + fd = n->nfile.fd; + if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) && + n->ndup.dupfd == fd) + continue; /* redirect from/to same file descriptor */ + + newfd = openredirect(n); + if (fd == newfd) + continue; + if (sv && *(p = &sv->renamed[fd]) == EMPTY) { + int i = fcntl(fd, F_DUPFD, 10); + if (i == -1) { + i = errno; + if (i != EBADF) { + const char *m = strerror(i); + close(newfd); + error("%d: %s", fd, m); + /* NOTREACHED */ + } + } else { + *p = i; + close(fd); + } + } else { + close(fd); + } +#ifdef notyet + dupredirect(n, newfd, memory); +#else + dupredirect(n, newfd); +#endif + } while ((n = n->nfile.next)); + INTON; +#ifdef notyet + if (memory[1]) + out1 = &memout; + if (memory[2]) + out2 = &memout; +#endif + if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0) + preverrout.fd = sv->renamed[2]; +} + + +STATIC int +openredirect(union node *redir) +{ + char *fname; + int f; + + switch (redir->nfile.type) { + case NFROM: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_RDONLY)) < 0) + goto eopen; + break; + case NFROMTO: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0) + goto ecreate; + break; + case NTO: + /* Take care of noclobber mode. */ + if (Cflag) { + fname = redir->nfile.expfname; + if ((f = noclobberopen(fname)) < 0) + goto ecreate; + break; + } + /* FALLTHROUGH */ + case NCLOBBER: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0) + goto ecreate; + break; + case NAPPEND: + fname = redir->nfile.expfname; + if ((f = open64(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0) + goto ecreate; + break; + default: +#ifdef DEBUG + abort(); +#endif + /* Fall through to eliminate warning. */ + case NTOFD: + case NFROMFD: + f = -1; + break; + case NHERE: + case NXHERE: + f = openhere(redir); + break; + } + + return f; +ecreate: + error("cannot create %s: %s", fname, errmsg(errno, E_CREAT)); +eopen: + error("cannot open %s: %s", fname, errmsg(errno, E_OPEN)); +} + + +STATIC void +#ifdef notyet +dupredirect(redir, f, memory) +#else +dupredirect(redir, f) +#endif + union node *redir; + int f; +#ifdef notyet + char memory[10]; +#endif + { + int fd = redir->nfile.fd; + +#ifdef notyet + memory[fd] = 0; +#endif + if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) { + if (redir->ndup.dupfd >= 0) { /* if not ">&-" */ +#ifdef notyet + if (memory[redir->ndup.dupfd]) + memory[fd] = 1; + else +#endif + copyfd(redir->ndup.dupfd, fd); + } + return; + } + + if (f != fd) { + copyfd(f, fd); + close(f); + } + return; +} + + +/* + * 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(union node *redir) +{ + int pip[2]; + size_t len = 0; + + if (pipe(pip) < 0) + error("Pipe call failed"); + if (redir->type == NHERE) { + len = strlen(redir->nhere.doc->narg.text); + if (len <= PIPESIZE) { + xwrite(pip[1], redir->nhere.doc->narg.text, len); + goto out; + } + } + if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { + close(pip[0]); + signal(SIGINT, SIG_IGN); + signal(SIGQUIT, SIG_IGN); + signal(SIGHUP, SIG_IGN); +#ifdef SIGTSTP + signal(SIGTSTP, SIG_IGN); +#endif + signal(SIGPIPE, SIG_DFL); + if (redir->type == NHERE) + xwrite(pip[1], redir->nhere.doc->narg.text, len); + else + expandhere(redir->nhere.doc, pip[1]); + _exit(0); + } +out: + close(pip[1]); + return pip[0]; +} + + + +/* + * Undo the effects of the last redirection. + */ + +void +popredir(int drop) +{ + struct redirtab *rp; + int i; + + if (--nullredirs >= 0) + return; + INTOFF; + rp = redirlist; + for (i = 0 ; i < 10 ; i++) { + if (rp->renamed[i] != EMPTY) { + if (!drop) { + close(i); + copyfd(rp->renamed[i], i); + } + close(rp->renamed[i]); + } + } + redirlist = rp->next; + nullredirs = rp->nullredirs; + ckfree(rp); + INTON; +} + +/* + * Undo all redirections. Called on error or interrupt. + */ + +#ifdef mkinit + +INCLUDE "redir.h" + +RESET { + clearredir(0); +} + +#endif + +/* + * Discard all saved file descriptors. + */ + +void +clearredir(int drop) +{ + for (;;) { + nullredirs = 0; + if (!redirlist) + break; + popredir(drop); + } +} + + + +/* + * 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(int from, int to) +{ + int newfd; + + newfd = fcntl(from, F_DUPFD, to); + if (newfd < 0) { + int errno2 = errno; + if (errno2 == EMFILE) + return EMPTY; + else + error("%d: %s", from, strerror(errno2)); + } + return newfd; +} + + +/* + * Open a file in noclobber mode. + * The code was copied from bash. + */ +int +noclobberopen(fname) + const char *fname; +{ + int r, fd; + struct stat64 finfo, finfo2; + + /* + * If the file exists and is a regular file, return an error + * immediately. + */ + r = stat64(fname, &finfo); + if (r == 0 && S_ISREG(finfo.st_mode)) { + errno = EEXIST; + return -1; + } + + /* + * If the file was not present (r != 0), make sure we open it + * exclusively so that if it is created before we open it, our open + * will fail. Make sure that we do not truncate an existing file. + * Note that we don't turn on O_EXCL unless the stat failed -- if the + * file was not a regular file, we leave O_EXCL off. + */ + if (r != 0) + return open64(fname, O_WRONLY|O_CREAT|O_EXCL, 0666); + fd = open64(fname, O_WRONLY|O_CREAT, 0666); + + /* If the open failed, return the file descriptor right away. */ + if (fd < 0) + return fd; + + /* + * OK, the open succeeded, but the file may have been changed from a + * non-regular file to a regular file between the stat and the open. + * We are assuming that the O_EXCL open handles the case where FILENAME + * did not exist and is symlinked to an existing file between the stat + * and open. + */ + + /* + * If we can open it and fstat the file descriptor, and neither check + * revealed that it was a regular file, and the file has not been + * replaced, return the file descriptor. + */ + if (fstat64(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) && + finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino) + return fd; + + /* The file has been replaced. badness. */ + close(fd); + errno = EEXIST; + return -1; +} + + +int +redirectsafe(union node *redir, int flags) +{ + int err; + volatile int saveint; + struct jmploc *volatile savehandler = handler; + struct jmploc jmploc; + + SAVEINT(saveint); + if (!(err = setjmp(jmploc.loc) * 2)) { + handler = &jmploc; + redirect(redir, flags); + } + handler = savehandler; + if (err && exception != EXERROR) + longjmp(handler->loc, 1); + RESTOREINT(saveint); + return err; +} |