Enhance get_file API to return info about input and output and to enable extensions to create already-opened files or sockets.

4 files changed, 104 insertions, 11 deletions

diff --git a/extension/ChangeLog b/extension/ChangeLog
index 5d278f6c..b8e68674 100644
--- a/extension/ChangeLog
+++ b/extension/ChangeLog
@@ -1,3 +1,15 @@
+2014-11-06         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
+	* errno.c (do_errno2name, do_name2errno): Remove unused variable 'str'.
+	* select.c (do_signal): Remove unused variable 'override'.
+	(grabfd): New helper function to map a gawk file to the appropriate
+	fd for use in the arguments to selectd.
+	(do_select): get_file has 3 new arguments and returns info about both
+	the input and output buf.
+	(do_set_non_blocking): Support changes to get_file API.
+	* testext.c (test_get_file): New test function to check that extension
+	file creation via the get_file API is working.
+
 2014-11-05         Andrew J. Schorr     <aschorr@telemetry-investments.com>
 
 	* select.c (set_retry): New function to set PROCINFO[<name>, "RETRY"].
diff --git a/extension/errno.c b/extension/errno.c
index 2eafa437..5dc15d79 100644
--- a/extension/errno.c
+++ b/extension/errno.c
@@ -86,7 +86,6 @@ static awk_value_t *
 do_errno2name(int nargs, awk_value_t *result)
 {
 	awk_value_t errnum;
-	const char *str;
 
 	if (do_lint && nargs > 1)
 		lintwarn(ext_id, _("errno2name: called with too many arguments"));
@@ -112,7 +111,6 @@ static awk_value_t *
 do_name2errno(int nargs, awk_value_t *result)
 {
 	awk_value_t err;
-	const char *str;
 
 	if (do_lint && nargs > 1)
 		lintwarn(ext_id, _("name2errno: called with too many arguments"));
diff --git a/extension/select.c b/extension/select.c
index 1752ee34..597b3a6b 100644
--- a/extension/select.c
+++ b/extension/select.c
@@ -223,7 +223,6 @@ do_signal(int nargs, awk_value_t *result)
 	
 #ifdef HAVE_SIGACTION
 	{
-		awk_value_t override;
 		struct sigaction sa, prev;
 		sa.sa_handler = func;
 		sigfillset(& sa.sa_mask);  /* block all signals in handler */
@@ -307,6 +306,27 @@ do_kill(int nargs, awk_value_t *result)
 #endif
 }
 
+static int
+grabfd(int i, const awk_input_buf_t *ibuf, const awk_output_buf_t *obuf, const char *fnm, const char *ftp)
+{
+	switch (i) {
+	case 0:	/* read */
+		return ibuf ? ibuf->fd : -1;
+	case 1:	/* write */
+		return obuf ? fileno(obuf->fp) : -1;
+	case 2: /* except */
+		if (ibuf) {
+			if (obuf && ibuf->fd != fileno(obuf->fp))
+				warning(ext_id, _("select: `%s', `%s' in `except' array has clashing fds, using input %d, not output %d"), fnm, ftp, ibuf->fd, fileno(obuf->fp));
+			return ibuf->fd;
+		}
+		if (obuf)
+			return fileno(obuf->fp);
+		break;
+	}
+	return -1;
+}
+
 /*  do_select --- I/O multiplexing */
 
 static awk_value_t *
@@ -362,9 +382,11 @@ do_select(int nargs, awk_value_t *result)
 				if (((EL.value.val_type == AWK_UNDEFINED) || ((EL.value.val_type == AWK_STRING) && ! EL.value.str_value.len)) && (integer_string(EL.index.str_value.str, &x) == 0) && (x >= 0))
 					fds[i].array2fd[j] = x;
 				else if (EL.value.val_type == AWK_STRING) {
-					const awk_input_buf_t *buf;
-					if ((buf = get_file(EL.index.str_value.str, EL.index.str_value.len, EL.value.str_value.str, EL.value.str_value.len)) != NULL)
-						fds[i].array2fd[j] = buf->fd;
+					const awk_input_buf_t *ibuf;
+					const awk_output_buf_t *obuf;
+					int fd;
+					if (get_file(EL.index.str_value.str, EL.index.str_value.len, EL.value.str_value.str, EL.value.str_value.len, -1, &ibuf, &obuf) && ((fd = grabfd(i, ibuf, obuf, EL.index.str_value.str, EL.value.str_value.str)) >= 0))
+						fds[i].array2fd[j] = fd;
 					else
 						warning(ext_id, _("select: get_file(`%s', `%s') failed in `%s' array"), EL.index.str_value.str, EL.value.str_value.str, argname[i]);
 				}
@@ -566,11 +588,12 @@ do_set_non_blocking(int nargs, awk_value_t *result)
 	else if (get_argument(0, AWK_STRING, & cmd) &&
 		(get_argument(1, AWK_STRING, & cmdtype) ||
 			(! cmd.str_value.len && (nargs == 1)))) {
-		const awk_input_buf_t *buf;
-		if ((buf = get_file(cmd.str_value.str, cmd.str_value.len, cmdtype.str_value.str, cmdtype.str_value.len)) != NULL) {
-			int rc = set_non_blocking(buf->fd);
-			if (rc == 0)
-				set_retry(buf->name);
+		const awk_input_buf_t *ibuf;
+		const awk_output_buf_t *obuf;
+		if (get_file(cmd.str_value.str, cmd.str_value.len, cmdtype.str_value.str, cmdtype.str_value.len, -1, &ibuf, &obuf)) {
+			int rc = set_non_blocking(ibuf ? ibuf->fd : fileno(obuf->fp));
+			if (rc == 0 && ibuf)
+				set_retry(ibuf->name);
 			return make_number(rc, result);
 		}
 		warning(ext_id, _("set_non_blocking: get_file(`%s', `%s') failed"), cmd.str_value.str, cmdtype.str_value.str);
diff --git a/extension/testext.c b/extension/testext.c
index 7462265b..3ac1f124 100644
--- a/extension/testext.c
+++ b/extension/testext.c
@@ -37,6 +37,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <fcntl.h>
 
 #include "gawkapi.h"
 
@@ -710,6 +711,7 @@ BEGIN {
 	ret = test_indirect_vars()	# should get correct value of NR
 	printf("test_indirect_var() return %d\n", ret)
 	delete ARGV[1]
+	print ""
 }
 */
 
@@ -742,6 +744,63 @@ out:
 	return result;
 }
 
+/*
+BEGIN {
+	outfile = "testexttmp.txt"
+	alias = ".test.alias"
+	print "line 1" > outfile
+	print "line 2" > outfile
+	print "line 3" > outfile
+	close(outfile)
+	ret = test_get_file(outfile, alias)
+	printf "test_get_file returned %d\n", ret
+	nr = 0
+	while ((getline < alias) > 0)
+		printf "File [%s] nr [%s]: %s\n", alias, ++nr, $0
+	close(alias)
+	system("rm " outfile)
+	print ""
+}
+*/
+
+/* test_get_file --- test that we can create a file */
+
+static awk_value_t *
+test_get_file(int nargs, awk_value_t *result)
+{
+	awk_value_t filename, alias;
+	int fd;
+	const awk_input_buf_t *ibuf;
+	const awk_output_buf_t *obuf;
+
+	if (nargs != 2) {
+		printf("%s: nargs not right (%d should be 2)\n", __func__, nargs);
+		return make_number(-1.0, result);
+	}
+
+	if (! get_argument(0, AWK_STRING, & filename)) {
+		printf("%s: cannot get first arg\n", __func__);
+		return make_number(-1.0, result);
+	}
+	if (! get_argument(1, AWK_STRING, & alias)) {
+		printf("%s: cannot get first arg\n", __func__);
+		return make_number(-1.0, result);
+	}
+	if ((fd = open(filename.str_value.str, O_RDONLY)) < 0) {
+		printf("%s: open(%s) failed\n", __func__, filename.str_value.str);
+		return make_number(-1.0, result);
+	}
+	if (! get_file(alias.str_value.str, strlen(alias.str_value.str), "<", 1, fd, &ibuf, &obuf)) {
+		printf("%s: get_file(%s) failed\n", __func__, alias.str_value.str);
+		return make_number(-1.0, result);
+	}
+	if (! ibuf || ibuf->fd != fd) {
+		printf("%s: get_file(%s) returned fd %d instead of %d\n", __func__, alias.str_value.str, ibuf ? ibuf->fd : -1, fd);
+		return make_number(-1.0, result);
+	}
+	return make_number(0.0, result);
+}
+
 /* fill_in_array --- fill in a new array */
 
 static void
@@ -837,6 +896,7 @@ static awk_ext_func_t func_table[] = {
 	{ "test_scalar", test_scalar, 1 },
 	{ "test_scalar_reserved", test_scalar_reserved, 0 },
 	{ "test_indirect_vars", test_indirect_vars, 0 },
+	{ "test_get_file", test_get_file, 2 },
 };
 
 /* init_testext --- additional initialization function */