fix issue with redirections to bash input file descriptor; new minimal chmod builtin; posix mode change for kill builtin return status; perform additional validation on brace expansion sequence expressions

examples/loadables/Makefile.in

@@ -103,8 +103,8 @@ INC = -I. -I.. -I$(topdir) -I$(topdir)/lib -I$(topdir)/builtins -I${srcdir} \
 ALLPROG = print truefalse sleep finfo logname basename dirname fdflags \
 	  tty pathchk tee head mkdir rmdir mkfifo mktemp printenv id whoami \
 	  uname sync push ln unlink realpath strftime mypid setpgid seq rm \
-	  accept csv dsv cut stat getconf kv strptime
-OTHERPROG = necho hello cat pushd asort fltexpr
+	  accept csv dsv cut stat getconf kv strptime chmod
+OTHERPROG = necho hello cat pushd asort fltexpr 
 
 SUBDIRS = perl
 
@@ -238,6 +238,9 @@ strftime:	strftime.o
 strptime:	strptime.o
 	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ strptime.o $(SHOBJ_LIBS)
 
+chmod:	chmod.o
+	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ chmod.o $(SHOBJ_LIBS)
+
 mypid:	mypid.o
 	$(SHOBJ_LD) $(SHOBJ_LDFLAGS) $(SHOBJ_XLDFLAGS) -o $@ mypid.o $(SHOBJ_LIBS)
 
@@ -319,7 +322,7 @@ OBJS = print.o truefalse.o accept.o sleep.o finfo.o getconf.o logname.o \
        basename.o dirname.o tty.o pathchk.o tee.o head.o rmdir.o necho.o \
        hello.o cat.o csv.o dsv.o kv.o cut.o printenv.o id.o whoami.o uname.o \
        sync.o push.o mkdir.o mktemp.o realpath.o strftime.o setpgid.o stat.o \
-       fdflags.o seq.o asort.o strptime.o        
+       fdflags.o seq.o asort.o strptime.o chmod.o
 
 ${OBJS}:	${BUILD_DIR}/config.h
 
@@ -340,6 +343,7 @@ rmdir.o: rmdir.c
 necho.o: necho.c
 hello.o: hello.c
 cat.o: cat.c
+chmod.o: chmod.c
 csv.o: csv.c
 dsv.o: dsv.c
 kv.o: kv.c

examples/loadables/chmod.c

@@ -0,0 +1,156 @@
+/* chmod - change file mode bits */
+
+/* See Makefile for compilation details. */
+
+/*
+   Copyright (C) 2024 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>
+
+#include "bashtypes.h"
+#include "posixstat.h"
+#include <errno.h>
+#include <stdio.h>
+#include "bashansi.h"
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+#include "common.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#define ISOCTAL(c)	((c) >= '0' && (c) <= '7')
+
+extern int parse_symbolic_mode (char *, mode_t);
+
+#define STANDARD_BITS	(S_IRWXU | S_IRWXG | S_IRWXO)
+#define ALLBITS (STANDARD_BITS | S_ISUID| S_ISGID | S_ISVTX)
+
+int
+chmod_builtin (WORD_LIST *list)
+{
+  int opt, nmode, lmode, rval;
+  char *mode;
+  struct stat st;
+  WORD_LIST *l;
+
+  reset_internal_getopt ();
+  mode = (char *)NULL;
+  while ((opt = internal_getopt(list, "fhvRHLP")) != -1)
+    switch (opt)
+      {
+	CASE_HELPOPT;
+	default:
+	  return (EX_DISKFALLBACK);
+      }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  mode = list->word->word;
+  list = list->next;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  nmode = -1;
+  if (ISOCTAL (*mode))	/* octal number */
+    {
+      nmode = read_octal (mode);
+      if (nmode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+  else 				/* test for valid symbolic mode */
+    {
+      /* initial bits are a=rwx; the mode argument modifies them */
+      lmode = parse_symbolic_mode (mode, ALLBITS);
+      if (lmode < 0)
+	{
+	  builtin_error ("invalid file mode: %s", mode);
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  for (rval = EXECUTION_SUCCESS, l = list; l; l = l->next)
+    {
+      lmode = nmode;
+      if (stat (l->word->word, &st) < 0)
+	{
+	  builtin_error ("`%s': cannot stat: %s", l->word->word, strerror (errno));
+	  rval = EXECUTION_FAILURE;
+	  continue;
+	}
+
+      if (lmode == -1)
+	{
+	  lmode = parse_symbolic_mode (mode, st.st_mode & ALLBITS);
+	  if (lmode < 0)
+	    {
+	      builtin_error ("`%s': invalid file mode: %s", l->word->word, mode);
+	      rval = EXECUTION_FAILURE;
+	      continue;
+	    }
+	}
+
+      if (chmod (l->word->word, lmode))
+	{
+	  builtin_error ("`%s': cannot change mode: %s", l->word->word, strerror (errno));
+	  rval = EXECUTION_FAILURE;
+	  continue;
+	}
+    }
+  return rval;
+}
+
+char *chmod_doc[] = {
+	"Change file mode bits.",
+	"",
+	"Change file mode bits.  Change the mode bits of files named as",
+	"arguments, in the order specified, as specified by MODE."
+	"The MODE argument may be an octal number or a symbolic mode like",
+	"that described in chmod(1).  If a symbolic mode is used, the",
+	"operations are interpreted relative to an initial mode of \"a=rwx\".",
+	"",
+	"The return value is 0 unless an error occurs.",
+	(char *)NULL
+};
+
+struct builtin chmod_struct = {
+	"chmod",
+	chmod_builtin,
+	BUILTIN_ENABLED,
+	chmod_doc,
+	"chmod [-R] mode file [file...]",
+	0
+};