Add os_isreadable function for future use.

8 files changed, 89 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index a7368de0..44de58f9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 2012-07-26         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* awk.h (set_RT_to_null, set_RT): Declare functions.
+	(os_isreadable): Declare function.
 	* io.c (set_RT_to_null, set_RT): New functions.
 	(iop_close): Init ret to zero.
 	* gawkapi.c (api_register_input_parser): Check for null pointer.
diff --git a/awk.h b/awk.h
index ebdbe777..3b7129fa 100644
--- a/awk.h
+++ b/awk.h
@@ -1532,6 +1532,7 @@ extern int os_devopen(const char *name, int flag);
 extern void os_close_on_exec(int fd, const char *name, const char *what, const char *dir);
 extern int os_isatty(int fd);
 extern int os_isdir(int fd);
+extern int os_isreadable(int fd);
 extern int os_is_setuid(void);
 extern int os_setbinmode(int fd, int mode);
 extern void os_restore_mode(int fd);
diff --git a/pc/ChangeLog b/pc/ChangeLog
index 1eb51812..43221928 100644
--- a/pc/ChangeLog
+++ b/pc/ChangeLog
@@ -1,3 +1,7 @@
+2012-07-26         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* gawkmisc.pc (os_isreadable): New function.
+
 2012-05-06         Eli Zaretskii  <eliz@gnu.org>
 
 	* config.sed: Update DJGPP -> __DJGPP__.
diff --git a/pc/gawkmisc.pc b/pc/gawkmisc.pc
index b368e81f..999167ca 100644
--- a/pc/gawkmisc.pc
+++ b/pc/gawkmisc.pc
@@ -232,6 +232,31 @@ int fd;
 	return (fstat(fd, &sbuf) == 0 && S_ISDIR(sbuf.st_mode));
 }
 
+/* os_isreadable --- fd can be read from */
+
+int
+os_isreadable(int fd)
+{
+	struct stat sbuf;
+
+	if (fstat(fd, &sbuf) != 0)
+		return false;
+
+	switch (sbuf.st_mode & S_IFMT) {
+	case S_IFREG:
+	case S_IFCHR:	/* ttys, /dev/null, .. */
+#ifdef S_IFSOCK
+	case S_IFSOCK:
+#endif
+#ifdef S_IFIFO
+	case S_IFIFO:
+#endif
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* os_is_setuid --- true if running setuid root */
 
 int
diff --git a/posix/ChangeLog b/posix/ChangeLog
index bf36414f..a3ee87db 100644
--- a/posix/ChangeLog
+++ b/posix/ChangeLog
@@ -1,3 +1,7 @@
+2012-07-26         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* gawkmisc.c (os_isreadable): New function.
+
 2012-05-11         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* gawkmisc.c: Use `bool', `true', and `false' everywhere.
diff --git a/posix/gawkmisc.c b/posix/gawkmisc.c
index 3baf852e..87a6747c 100644
--- a/posix/gawkmisc.c
+++ b/posix/gawkmisc.c
@@ -204,6 +204,31 @@ os_isdir(int fd)
 	return (fstat(fd, &sbuf) == 0 && S_ISDIR(sbuf.st_mode));
 }
 
+/* os_isreadable --- fd can be read from */
+
+int
+os_isreadable(int fd)
+{
+	struct stat sbuf;
+
+	if (fstat(fd, &sbuf) != 0)
+		return false;
+
+	switch (sbuf.st_mode & S_IFMT) {
+	case S_IFREG:
+	case S_IFCHR:	/* ttys, /dev/null, .. */
+#ifdef S_IFSOCK
+	case S_IFSOCK:
+#endif
+#ifdef S_IFIFO
+	case S_IFIFO:
+#endif
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* os_is_setuid --- true if running setuid root */
 
 int
diff --git a/vms/ChangeLog b/vms/ChangeLog
index 9988d34b..c4cb6ed9 100644
--- a/vms/ChangeLog
+++ b/vms/ChangeLog
@@ -1,3 +1,7 @@
+2012-07-26         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* gawkmisc.vms (os_isreadable): New function.
+
 2012-03-29         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* config.h: Add definition for _Noreturn.
diff --git a/vms/gawkmisc.vms b/vms/gawkmisc.vms
index 90b2530b..f373b5f2 100644
--- a/vms/gawkmisc.vms
+++ b/vms/gawkmisc.vms
@@ -144,6 +144,31 @@ int fd;
 	return (fstat(fd, &sbuf) == 0 && S_ISDIR(sbuf.st_mode));
 }
 
+/* os_isreadable --- fd can be read from */
+
+int
+os_isreadable(int fd)
+{
+	struct stat sbuf;
+
+	if (fstat(fd, &sbuf) != 0)
+		return false;
+
+	switch (sbuf.st_mode & S_IFMT) {
+	case S_IFREG:
+	case S_IFCHR:	/* ttys, /dev/null, .. */
+#ifdef S_IFSOCK
+	case S_IFSOCK:
+#endif
+#ifdef S_IFIFO
+	case S_IFIFO:
+#endif
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* os_is_setuid --- true if running setuid root */
 
 int