summaryrefslogtreecommitdiffstats
path: root/examples/loadables/fdflags.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--examples/loadables/fdflags.c336
1 files changed, 336 insertions, 0 deletions
diff --git a/examples/loadables/fdflags.c b/examples/loadables/fdflags.c
new file mode 100644
index 0000000..f309466
--- /dev/null
+++ b/examples/loadables/fdflags.c
@@ -0,0 +1,336 @@
+/* Loadable builtin to get and set file descriptor flags. */
+
+/* See Makefile for compilation details. */
+
+/*
+ Copyright (C) 2017 Free Software Foundation, Inc.
+
+ This file is part of GNU Bash.
+ Bash is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Bash is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Bash. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
+#include "bashansi.h"
+#include <stdio.h>
+
+#include "loadables.h"
+
+static const struct
+{
+ const char *name;
+ int value;
+} file_flags[] =
+{
+#ifdef O_APPEND
+ { "append", O_APPEND },
+#endif
+#ifdef O_ASYNC
+ { "async", O_ASYNC },
+#endif
+#ifdef O_SYNC
+ { "sync", O_SYNC },
+#endif
+#ifdef O_NONBLOCK
+ { "nonblock", O_NONBLOCK },
+#endif
+#ifdef O_FSYNC
+ { "fsync", O_FSYNC },
+#endif
+#ifdef O_DSYNC
+ { "dsync", O_DSYNC },
+#endif
+#ifdef O_RSYNC
+ { "rsync", O_RSYNC },
+#endif
+#ifdef O_ALT_IO
+ { "altio", O_ALT_IO },
+#endif
+#ifdef O_DIRECT
+ { "direct", O_DIRECT },
+#endif
+#ifdef O_NOATIME
+ { "noatime", O_NOATIME },
+#endif
+#ifdef O_NOSIGPIPE
+ { "nosigpipe", O_NOSIGPIPE },
+#endif
+#ifdef O_CLOEXEC
+ { "cloexec", O_CLOEXEC },
+#endif
+};
+
+#define N_FLAGS (sizeof (file_flags) / sizeof (file_flags[0]))
+
+#ifndef errno
+extern int errno;
+#endif
+
+/* FIX THIS */
+static int
+getallflags ()
+{
+ int i, allflags;
+
+ for (i = allflags = 0; i < N_FLAGS; i++)
+ allflags |= file_flags[i].value;
+ return allflags;
+}
+
+static int
+getflags(int fd, int p)
+{
+ int c, f;
+ int allflags;
+
+ if ((c = fcntl(fd, F_GETFD)) == -1)
+ {
+ if (p)
+ builtin_error("can't get status for fd %d: %s", fd, strerror(errno));
+ return -1;
+ }
+
+ if ((f = fcntl(fd, F_GETFL)) == -1)
+ {
+ if (p)
+ builtin_error("Can't get flags for fd %d: %s", fd, strerror(errno));
+ return -1;
+ }
+
+ if (c)
+ f |= O_CLOEXEC;
+
+ return f & getallflags();
+}
+
+static void
+printone(int fd, int p, int verbose)
+{
+ int f;
+ size_t i;
+
+ if ((f = getflags(fd, p)) == -1)
+ return;
+
+ printf ("%d:", fd);
+
+ for (i = 0; i < N_FLAGS; i++)
+ {
+ if (f & file_flags[i].value)
+ {
+ printf ("%s%s", verbose ? "+" : "", file_flags[i].name);
+ f &= ~file_flags[i].value;
+ }
+ else if (verbose)
+ printf ( "-%s", file_flags[i].name);
+ else
+ continue;
+
+ if (f || (verbose && i != N_FLAGS - 1))
+ putchar (',');
+ }
+ printf ("\n");
+}
+
+static int
+parseflags(char *s, int *p, int *n)
+{
+ int f, *v;
+ size_t i;
+
+ f = 0;
+ *p = *n = 0;
+
+ for (s = strtok(s, ","); s; s = strtok(NULL, ","))
+ {
+ switch (*s)
+ {
+ case '+':
+ v = p;
+ s++;
+ break;
+ case '-':
+ v = n;
+ s++;
+ break;
+ default:
+ v = &f;
+ break;
+ }
+
+ for (i = 0; i < N_FLAGS; i++)
+ if (strcmp(s, file_flags[i].name) == 0)
+ {
+ *v |= file_flags[i].value;
+ break;
+ }
+ if (i == N_FLAGS)
+ builtin_error("invalid flag `%s'", s);
+ }
+
+ return f;
+}
+
+static void
+setone(int fd, char *v, int verbose)
+{
+ int f, n, pos, neg, cloexec;
+
+ f = getflags(fd, 1);
+ if (f == -1)
+ return;
+
+ parseflags(v, &pos, &neg);
+
+ cloexec = -1;
+ if ((pos & O_CLOEXEC) && (f & O_CLOEXEC) == 0)
+ cloexec = FD_CLOEXEC;
+ if ((neg & O_CLOEXEC) && (f & O_CLOEXEC))
+ cloexec = 0;
+ if (cloexec != -1 && fcntl(fd, F_SETFD, cloexec) == -1)
+ builtin_error("can't set status for fd %d: %s", fd, strerror(errno));
+
+ pos &= ~O_CLOEXEC;
+ neg &= ~O_CLOEXEC;
+ f &= ~O_CLOEXEC;
+
+ n = f;
+ n |= pos;
+ n &= ~neg;
+
+ if (n != f && fcntl(fd, F_SETFL, n) == -1)
+ builtin_error("can't set flags for fd %d: %s", fd, strerror(errno));
+}
+
+static int
+getmaxfd ()
+{
+ int maxfd, ignore;
+
+#ifdef F_MAXFD
+ maxfd = fcntl (0, F_MAXFD);
+ if (maxfd > 0)
+ return maxfd;
+#endif
+
+ maxfd = getdtablesize ();
+ if (maxfd <= 0)
+ maxfd = HIGH_FD_MAX;
+ for (maxfd--; maxfd > 0; maxfd--)
+ if (fcntl (maxfd, F_GETFD, &ignore) != -1)
+ break;
+
+ return maxfd;
+}
+
+int
+fdflags_builtin (WORD_LIST *list)
+{
+ int opt, maxfd, i, num, verbose, setflag;
+ char *setspec;
+ WORD_LIST *l;
+ intmax_t inum;
+
+ setflag = verbose = 0;
+ reset_internal_getopt ();
+ while ((opt = internal_getopt (list, "s:v")) != -1)
+ {
+ switch (opt)
+ {
+ case 's':
+ setflag = 1;
+ setspec = list_optarg;
+ break;
+ case 'v':
+ verbose = 1;
+ break;
+ CASE_HELPOPT;
+ default:
+ builtin_usage ();
+ return (EX_USAGE);
+ }
+
+ }
+ list = loptend;
+
+ /* Maybe we could provide some default here, but we don't yet. */
+ if (list == 0 && setflag)
+ return (EXECUTION_SUCCESS);
+
+ if (list == 0)
+ {
+ maxfd = getmaxfd ();
+ if (maxfd < 0)
+ {
+ builtin_error ("can't get max fd: %s", strerror (errno));
+ return (EXECUTION_FAILURE);
+ }
+ for (i = 0; i < maxfd; i++)
+ printone (i, 0, verbose);
+ return (EXECUTION_SUCCESS);
+ }
+
+ opt = EXECUTION_SUCCESS;
+ for (l = list; l; l = l->next)
+ {
+ if (legal_number (l->word->word, &inum) == 0 || inum < 0)
+ {
+ builtin_error ("%s: invalid file descriptor", l->word->word);
+ opt = EXECUTION_FAILURE;
+ continue;
+ }
+ num = inum; /* truncate to int */
+ if (setflag)
+ setone (num, setspec, verbose);
+ else
+ printone (num, 1, verbose);
+ }
+
+ return (opt);
+}
+
+char *fdflags_doc[] =
+{
+ "Display and modify file descriptor flags.",
+ "",
+ "Display or, if the -s option is supplied, set flags for each file",
+ "descriptor supplied as an argument. If the -v option is supplied,",
+ "the display is verbose, including each settable option name in the",
+ "form of a string such as that accepted by the -s option.",
+ "",
+ "The -s option accepts a string with a list of flag names, each preceded",
+ "by a `+' (set) or `-' (unset). Those changes are applied to each file",
+ "descriptor supplied as an argument.",
+ "",
+ "If no file descriptor arguments are supplied, the displayed information",
+ "consists of the status of flags for each of the shell's open files.",
+ (char *)NULL
+};
+
+/* The standard structure describing a builtin command. bash keeps an array
+ of these structures. The flags must include BUILTIN_ENABLED so the
+ builtin can be used. */
+struct builtin fdflags_struct = {
+ "fdflags", /* builtin name */
+ fdflags_builtin, /* function implementing the builtin */
+ BUILTIN_ENABLED, /* initial flags for builtin */
+ fdflags_doc, /* array of long documentation strings. */
+ "fdflags [-v] [-s flags_string] [fd ...]", /* usage synopsis; becomes short_doc */
+ 0 /* reserved for internal use */
+};