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-rw-r--r--shell/ash.c962
1 files changed, 471 insertions, 491 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 5c9060cad..1de4cb50b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1593,6 +1593,21 @@ struct shparam {
static struct shparam shellparam; /* $@ current positional parameters */
+/*
+ * Free the list of positional parameters.
+ */
+static void
+freeparam(volatile struct shparam *param)
+{
+ char **ap;
+
+ if (param->malloc) {
+ for (ap = param->p; *ap; ap++)
+ free(*ap);
+ free(param->p);
+ }
+}
+
#if ENABLE_ASH_GETOPTS
static void
getoptsreset(const char *value)
@@ -2871,29 +2886,6 @@ static const char syntax_index_table[258] = {
#endif /* USE_SIT_FUNCTION */
-/* options.h */
-
-static void optschanged(void);
-static void setparam(char **);
-static void freeparam(volatile struct shparam *);
-static int shiftcmd(int, char **);
-static int setcmd(int, char **);
-static int nextopt(const char *);
-
-
-/* redir.h */
-
-/* flags passed to redirect */
-#define REDIR_PUSH 01 /* save previous values of file descriptors */
-#define REDIR_SAVEFD2 03 /* set preverrout */
-
-static void redirect(union node *, int);
-static void popredir(int);
-static void clearredir(int);
-static int copyfd(int, int);
-static int redirectsafe(union node *, int);
-
-
/* ============ Alias handling */
#if ENABLE_ASH_ALIAS
@@ -4622,6 +4614,357 @@ stoppedjobs(void)
}
+/* ============ redir.c
+ *
+ * Code for dealing with input/output redirection.
+ */
+
+#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
+
+/*
+ * Open a file in noclobber mode.
+ * The code was copied from bash.
+ */
+static int
+noclobberopen(const char *fname)
+{
+ int r, fd;
+ struct stat finfo, finfo2;
+
+ /*
+ * If the file exists and is a regular file, return an error
+ * immediately.
+ */
+ r = stat(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 open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
+ fd = open(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 (fstat(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;
+}
+
+/*
+ * 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.
+ */
+/* openhere needs this forward reference */
+static void expandhere(union node *arg, int fd);
+static int
+openhere(union node *redir)
+{
+ int pip[2];
+ size_t len = 0;
+
+ if (pipe(pip) < 0)
+ ash_msg_and_raise_error("Pipe call failed");
+ if (redir->type == NHERE) {
+ len = strlen(redir->nhere.doc->narg.text);
+ if (len <= PIPESIZE) {
+ full_write(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)
+ full_write(pip[1], redir->nhere.doc->narg.text, len);
+ else
+ expandhere(redir->nhere.doc, pip[1]);
+ _exit(0);
+ }
+ out:
+ close(pip[1]);
+ return pip[0];
+}
+
+static int
+openredirect(union node *redir)
+{
+ char *fname;
+ int f;
+
+ switch (redir->nfile.type) {
+ case NFROM:
+ fname = redir->nfile.expfname;
+ f = open(fname, O_RDONLY);
+ if (f < 0)
+ goto eopen;
+ break;
+ case NFROMTO:
+ fname = redir->nfile.expfname;
+ f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
+ if (f < 0)
+ goto ecreate;
+ break;
+ case NTO:
+ /* Take care of noclobber mode. */
+ if (Cflag) {
+ fname = redir->nfile.expfname;
+ f = noclobberopen(fname);
+ if (f < 0)
+ goto ecreate;
+ break;
+ }
+ /* FALLTHROUGH */
+ case NCLOBBER:
+ fname = redir->nfile.expfname;
+ f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
+ if (f < 0)
+ goto ecreate;
+ break;
+ case NAPPEND:
+ fname = redir->nfile.expfname;
+ f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
+ if (f < 0)
+ goto ecreate;
+ break;
+ default:
+#if 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:
+ ash_msg_and_raise_error("cannot create %s: %s", fname, errmsg(errno, "Directory nonexistent"));
+ eopen:
+ ash_msg_and_raise_error("cannot open %s: %s", fname, errmsg(errno, "No such file"));
+}
+
+/*
+ * 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.
+ */
+static int
+copyfd(int from, int to)
+{
+ int newfd;
+
+ newfd = fcntl(from, F_DUPFD, to);
+ if (newfd < 0) {
+ if (errno == EMFILE)
+ return EMPTY;
+ ash_msg_and_raise_error("%d: %m", from);
+ }
+ return newfd;
+}
+
+static void
+dupredirect(union node *redir, int f)
+{
+ int fd = redir->nfile.fd;
+
+ if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+ if (redir->ndup.dupfd >= 0) { /* if not ">&-" */
+ copyfd(redir->ndup.dupfd, fd);
+ }
+ return;
+ }
+
+ if (f != fd) {
+ copyfd(f, fd);
+ close(f);
+ }
+}
+
+/*
+ * 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.
+ */
+/* flags passed to redirect */
+#define REDIR_PUSH 01 /* save previous values of file descriptors */
+#define REDIR_SAVEFD2 03 /* set preverrout */
+static void
+redirect(union node *redir, int flags)
+{
+ union node *n;
+ struct redirtab *sv;
+ int i;
+ int fd;
+ int newfd;
+ int *p;
+ nullredirs++;
+ if (!redir) {
+ return;
+ }
+ sv = NULL;
+ INT_OFF;
+ 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) {
+ i = fcntl(fd, F_DUPFD, 10);
+
+ if (i == -1) {
+ i = errno;
+ if (i != EBADF) {
+ close(newfd);
+ errno = i;
+ ash_msg_and_raise_error("%d: %m", fd);
+ /* NOTREACHED */
+ }
+ } else {
+ *p = i;
+ close(fd);
+ }
+ } else {
+ close(fd);
+ }
+ dupredirect(n, newfd);
+ } while ((n = n->nfile.next));
+ INT_ON;
+ if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
+ preverrout_fd = sv->renamed[2];
+}
+
+/*
+ * Undo the effects of the last redirection.
+ */
+static void
+popredir(int drop)
+{
+ struct redirtab *rp;
+ int i;
+
+ if (--nullredirs >= 0)
+ return;
+ INT_OFF;
+ 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;
+ free(rp);
+ INT_ON;
+}
+
+/*
+ * Undo all redirections. Called on error or interrupt.
+ */
+
+/*
+ * Discard all saved file descriptors.
+ */
+static void
+clearredir(int drop)
+{
+ for (;;) {
+ nullredirs = 0;
+ if (!redirlist)
+ break;
+ popredir(drop);
+ }
+}
+
+static int
+redirectsafe(union node *redir, int flags)
+{
+ int err;
+ volatile int saveint;
+ struct jmploc *volatile savehandler = exception_handler;
+ struct jmploc jmploc;
+
+ SAVE_INT(saveint);
+ err = setjmp(jmploc.loc) * 2;
+ if (!err) {
+ exception_handler = &jmploc;
+ redirect(redir, flags);
+ }
+ exception_handler = savehandler;
+ if (err && exception != EXERROR)
+ longjmp(exception_handler->loc, 1);
+ RESTORE_INT(saveint);
+ return err;
+}
+
+
/* ============ Routines to expand arguments to commands
*
* We have to deal with backquotes, shell variables, and file metacharacters.
@@ -7475,6 +7818,58 @@ evalpipe(union node *n, int flags)
INT_ON;
}
+/*
+ * Controls whether the shell is interactive or not.
+ */
+static void
+setinteractive(int on)
+{
+ static int is_interactive;
+
+ if (++on == is_interactive)
+ return;
+ is_interactive = on;
+ setsignal(SIGINT);
+ setsignal(SIGQUIT);
+ setsignal(SIGTERM);
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
+ if (is_interactive > 1) {
+ /* Looks like they want an interactive shell */
+ static smallint do_banner;
+
+ if (!do_banner) {
+ out1fmt(
+ "\n\n"
+ "%s Built-in shell (ash)\n"
+ "Enter 'help' for a list of built-in commands."
+ "\n\n",
+ BB_BANNER);
+ do_banner = 1;
+ }
+ }
+#endif
+}
+
+#if ENABLE_FEATURE_EDITING_VI
+#define setvimode(on) do { \
+ if (on) line_input_state->flags |= VI_MODE; \
+ else line_input_state->flags &= ~VI_MODE; \
+} while (0)
+#else
+#define setvimode(on) viflag = 0 /* forcibly keep the option off */
+#endif
+
+static void
+optschanged(void)
+{
+#if DEBUG
+ opentrace();
+#endif
+ setinteractive(iflag);
+ setjobctl(mflag);
+ setvimode(viflag);
+}
+
static struct localvar *localvars;
/*
@@ -7894,7 +8289,7 @@ evalcommand(union node *cmd, int flags)
preverrout_fd = 2;
expredir(cmd->ncmd.redirect);
- status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH|REDIR_SAVEFD2);
+ status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);
path = vpath.text;
for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
@@ -8678,88 +9073,35 @@ changemail(const char *val)
/* ============ ??? */
/*
- * Take commands from a file. To be compatible we should do a path
- * search for the file, which is necessary to find sub-commands.
- */
-static char *
-find_dot_file(char *name)
-{
- char *fullname;
- const char *path = pathval();
- struct stat statb;
-
- /* don't try this for absolute or relative paths */
- if (strchr(name, '/'))
- return name;
-
- while ((fullname = padvance(&path, name)) != NULL) {
- if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
- /*
- * Don't bother freeing here, since it will
- * be freed by the caller.
- */
- return fullname;
- }
- stunalloc(fullname);
- }
-
- /* not found in the PATH */
- ash_msg_and_raise_error("%s: not found", name);
- /* NOTREACHED */
-}
-
-/*
- * Controls whether the shell is interactive or not.
+ * Set the shell parameters.
*/
static void
-setinteractive(int on)
+setparam(char **argv)
{
- static int is_interactive;
-
- if (++on == is_interactive)
- return;
- is_interactive = on;
- setsignal(SIGINT);
- setsignal(SIGQUIT);
- setsignal(SIGTERM);
-#if !ENABLE_FEATURE_SH_EXTRA_QUIET
- if (is_interactive > 1) {
- /* Looks like they want an interactive shell */
- static smallint do_banner;
+ char **newparam;
+ char **ap;
+ int nparam;
- if (!do_banner) {
- out1fmt(
- "\n\n"
- "%s Built-in shell (ash)\n"
- "Enter 'help' for a list of built-in commands."
- "\n\n",
- BB_BANNER);
- do_banner = 1;
- }
+ for (nparam = 0; argv[nparam]; nparam++);
+ ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap));
+ while (*argv) {
+ *ap++ = ckstrdup(*argv++);
}
+ *ap = NULL;
+ freeparam(&shellparam);
+ shellparam.malloc = 1;
+ shellparam.nparam = nparam;
+ shellparam.p = newparam;
+#if ENABLE_ASH_GETOPTS
+ shellparam.optind = 1;
+ shellparam.optoff = -1;
#endif
}
-#if ENABLE_FEATURE_EDITING_VI
-#define setvimode(on) do { \
- if (on) line_input_state->flags |= VI_MODE; \
- else line_input_state->flags &= ~VI_MODE; \
-} while (0)
-#else
-#define setvimode(on) viflag = 0 /* forcibly keep the option off */
-#endif
-
-static void
-optschanged(void)
-{
-#if DEBUG
- opentrace();
-#endif
- setinteractive(iflag);
- setjobctl(mflag);
- setvimode(viflag);
-}
-
+/*
+ * Process shell options. The global variable argptr contains a pointer
+ * to the argument list; we advance it past the options.
+ */
static void
minus_o(char *name, int val)
{
@@ -8779,7 +9121,6 @@ minus_o(char *name, int val)
out1fmt("%-16s%s\n", optnames(i),
optlist[i] ? "on" : "off");
}
-
static void
setoption(int flag, int val)
{
@@ -8794,11 +9135,6 @@ setoption(int flag, int val)
ash_msg_and_raise_error("Illegal option -%c", flag);
/* NOTREACHED */
}
-
-/*
- * Process shell options. The global variable argptr contains a pointer
- * to the argument list; we advance it past the options.
- */
static void
options(int cmdline)
{
@@ -8849,47 +9185,6 @@ options(int cmdline)
}
/*
- * Set the shell parameters.
- */
-static void
-setparam(char **argv)
-{
- char **newparam;
- char **ap;
- int nparam;
-
- for (nparam = 0; argv[nparam]; nparam++);
- ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap));
- while (*argv) {
- *ap++ = ckstrdup(*argv++);
- }
- *ap = NULL;
- freeparam(&shellparam);
- shellparam.malloc = 1;
- shellparam.nparam = nparam;
- shellparam.p = newparam;
-#if ENABLE_ASH_GETOPTS
- shellparam.optind = 1;
- shellparam.optoff = -1;
-#endif
-}
-
-/*
- * Free the list of positional parameters.
- */
-static void
-freeparam(volatile struct shparam *param)
-{
- char **ap;
-
- if (param->malloc) {
- for (ap = param->p; *ap; ap++)
- free(*ap);
- free(param->p);
- }
-}
-
-/*
* The shift builtin command.
*/
static int
@@ -10720,6 +11015,37 @@ cmdloop(int top)
return 0;
}
+/*
+ * Take commands from a file. To be compatible we should do a path
+ * search for the file, which is necessary to find sub-commands.
+ */
+static char *
+find_dot_file(char *name)
+{
+ char *fullname;
+ const char *path = pathval();
+ struct stat statb;
+
+ /* don't try this for absolute or relative paths */
+ if (strchr(name, '/'))
+ return name;
+
+ while ((fullname = padvance(&path, name)) != NULL) {
+ if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
+ /*
+ * Don't bother freeing here, since it will
+ * be freed by the caller.
+ */
+ return fullname;
+ }
+ stunalloc(fullname);
+ }
+
+ /* not found in the PATH */
+ ash_msg_and_raise_error("%s: not found", name);
+ /* NOTREACHED */
+}
+
static int
dotcmd(int argc, char **argv)
{
@@ -10982,352 +11308,6 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
}
-/* ============ redir.c
- *
- * Code for dealing with input/output redirection.
- */
-
-#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
-
-/*
- * Open a file in noclobber mode.
- * The code was copied from bash.
- */
-static int
-noclobberopen(const char *fname)
-{
- int r, fd;
- struct stat finfo, finfo2;
-
- /*
- * If the file exists and is a regular file, return an error
- * immediately.
- */
- r = stat(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 open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
- fd = open(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 (fstat(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;
-}
-
-/*
- * 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)
- ash_msg_and_raise_error("Pipe call failed");
- if (redir->type == NHERE) {
- len = strlen(redir->nhere.doc->narg.text);
- if (len <= PIPESIZE) {
- full_write(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)
- full_write(pip[1], redir->nhere.doc->narg.text, len);
- else
- expandhere(redir->nhere.doc, pip[1]);
- _exit(0);
- }
- out:
- close(pip[1]);
- return pip[0];
-}
-
-static int
-openredirect(union node *redir)
-{
- char *fname;
- int f;
-
- switch (redir->nfile.type) {
- case NFROM:
- fname = redir->nfile.expfname;
- f = open(fname, O_RDONLY);
- if (f < 0)
- goto eopen;
- break;
- case NFROMTO:
- fname = redir->nfile.expfname;
- f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
- if (f < 0)
- goto ecreate;
- break;
- case NTO:
- /* Take care of noclobber mode. */
- if (Cflag) {
- fname = redir->nfile.expfname;
- f = noclobberopen(fname);
- if (f < 0)
- goto ecreate;
- break;
- }
- /* FALLTHROUGH */
- case NCLOBBER:
- fname = redir->nfile.expfname;
- f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
- if (f < 0)
- goto ecreate;
- break;
- case NAPPEND:
- fname = redir->nfile.expfname;
- f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
- if (f < 0)
- goto ecreate;
- break;
- default:
-#if 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:
- ash_msg_and_raise_error("cannot create %s: %s", fname, errmsg(errno, "Directory nonexistent"));
- eopen:
- ash_msg_and_raise_error("cannot open %s: %s", fname, errmsg(errno, "No such file"));
-}
-
-static void
-dupredirect(union node *redir, int f)
-{
- int fd = redir->nfile.fd;
-
- if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
- if (redir->ndup.dupfd >= 0) { /* if not ">&-" */
- copyfd(redir->ndup.dupfd, fd);
- }
- return;
- }
-
- if (f != fd) {
- copyfd(f, fd);
- close(f);
- }
-}
-
-/*
- * 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.
- */
-static void
-redirect(union node *redir, int flags)
-{
- union node *n;
- struct redirtab *sv;
- int i;
- int fd;
- int newfd;
- int *p;
- nullredirs++;
- if (!redir) {
- return;
- }
- sv = NULL;
- INT_OFF;
- 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) {
- i = fcntl(fd, F_DUPFD, 10);
-
- if (i == -1) {
- i = errno;
- if (i != EBADF) {
- close(newfd);
- errno = i;
- ash_msg_and_raise_error("%d: %m", fd);
- /* NOTREACHED */
- }
- } else {
- *p = i;
- close(fd);
- }
- } else {
- close(fd);
- }
- dupredirect(n, newfd);
- } while ((n = n->nfile.next));
- INT_ON;
- if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
- preverrout_fd = sv->renamed[2];
-}
-
-/*
- * Undo the effects of the last redirection.
- */
-static void
-popredir(int drop)
-{
- struct redirtab *rp;
- int i;
-
- if (--nullredirs >= 0)
- return;
- INT_OFF;
- 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;
- free(rp);
- INT_ON;
-}
-
-/*
- * Undo all redirections. Called on error or interrupt.
- */
-
-/*
- * Discard all saved file descriptors.
- */
-static 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.
- */
-static int
-copyfd(int from, int to)
-{
- int newfd;
-
- newfd = fcntl(from, F_DUPFD, to);
- if (newfd < 0) {
- if (errno == EMFILE)
- return EMPTY;
- ash_msg_and_raise_error("%d: %m", from);
- }
- return newfd;
-}
-
-static int
-redirectsafe(union node *redir, int flags)
-{
- int err;
- volatile int saveint;
- struct jmploc *volatile savehandler = exception_handler;
- struct jmploc jmploc;
-
- SAVE_INT(saveint);
- err = setjmp(jmploc.loc) * 2;
- if (!err) {
- exception_handler = &jmploc;
- redirect(redir, flags);
- }
- exception_handler = savehandler;
- if (err && exception != EXERROR)
- longjmp(exception_handler->loc, 1);
- RESTORE_INT(saveint);
- return err;
-}
-
-
/* ============ trap.c */
/*
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-31 16:38:03 +0000