Start at non-fatal output via PROCINFO.

4 files changed, 86 insertions, 11 deletions

diff --git a/ChangeLog b/ChangeLog
index a9c7e555..35d73180 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2014-12-20         Arnold D. Robbins     <arnold@skeeve.com>
+
+	Enable non-fatal output on per-file or global basis,
+	via PROCINFO.
+
+	* awk.h (RED_NON_FATAL): New redirection flag.
+	* builtin.c (efwrite): If RED_NON_FATAL set, just set ERRNO and return.
+	(do_printf): Check errflg and if set, set ERRNO and return.
+	(do_print): Ditto.
+	(do_print_rec): Ditto.
+	* io.c (redflags2str): Update table.
+	(redirect): Check for global PROCINFO["nonfatal"] or for
+	PROCINFO[file, "nonfatal"] and don't fail on open if set.
+	Add RED_NON_FATAL to flags.
+	(in_PROCINFO): Make smarter and more general.
+
 2014-12-12        Stephen Davies         <sdavies@sdc.com.au>
 
 	Improve comment handling in pretty printing.
diff --git a/awk.h b/awk.h
index 41181529..ff3499cd 100644
--- a/awk.h
+++ b/awk.h
@@ -918,6 +918,7 @@ struct redirect {
 #		define	RED_PTY		512
 #		define	RED_SOCKET	1024
 #		define	RED_TCP		2048
+#		define	RED_NON_FATAL	4096
 	char *value;
 	FILE *ifp;	/* input fp, needed for PIPES_SIMULATED */
 	IOBUF *iop;
diff --git a/builtin.c b/builtin.c
index 21c6ed5c..b3f3f333 100644
--- a/builtin.c
+++ b/builtin.c
@@ -130,9 +130,12 @@ wrerror:
 		gawk_exit(EXIT_FATAL);
 
 	/* otherwise die verbosely */
-	fatal(_("%s to \"%s\" failed (%s)"), from,
-		rp ? rp->value : _("standard output"),
-		errno ? strerror(errno) : _("reason unknown"));
+	if ((rp->flag & RED_NON_FATAL) != 0) {
+		update_ERRNO_int(errno);
+	} else
+		fatal(_("%s to \"%s\" failed (%s)"), from,
+			rp ? rp->value : _("standard output"),
+			errno ? strerror(errno) : _("reason unknown"));
 }
 
 /* do_exp --- exponential function */
@@ -1633,7 +1636,7 @@ do_printf(int nargs, int redirtype)
 	FILE *fp = NULL;
 	NODE *tmp;
 	struct redirect *rp = NULL;
-	int errflg;	/* not used, sigh */
+	int errflg = 0;
 	NODE *redir_exp = NULL;
 
 	if (nargs == 0) {
@@ -1660,6 +1663,10 @@ do_printf(int nargs, int redirtype)
 		rp = redirect(redir_exp, redirtype, & errflg);
 		if (rp != NULL)
 			fp = rp->output.fp;
+		else if (errflg) {
+			update_ERRNO_int(errflg);
+			return;
+		}
 	} else if (do_debug)	/* only the debugger can change the default output */
 		fp = output_fp;
 	else
@@ -2072,7 +2079,7 @@ void
 do_print(int nargs, int redirtype)
 {
 	struct redirect *rp = NULL;
-	int errflg;	/* not used, sigh */
+	int errflg = 0;
 	FILE *fp = NULL;
 	int i;
 	NODE *redir_exp = NULL;
@@ -2087,6 +2094,10 @@ do_print(int nargs, int redirtype)
 		rp = redirect(redir_exp, redirtype, & errflg);
 		if (rp != NULL)
 			fp = rp->output.fp;
+		else if (errflg) {
+			update_ERRNO_int(errflg);
+			return;
+		}
 	} else if (do_debug)	/* only the debugger can change the default output */
 		fp = output_fp;
 	else
@@ -2142,7 +2153,7 @@ do_print_rec(int nargs, int redirtype)
 	FILE *fp = NULL;
 	NODE *f0;
 	struct redirect *rp = NULL;
-	int errflg;	/* not used, sigh */
+	int errflg = 0;
 	NODE *redir_exp = NULL;
 
 	assert(nargs == 0);
@@ -2162,6 +2173,11 @@ do_print_rec(int nargs, int redirtype)
 	if (! field0_valid)
 		(void) get_field(0L, NULL);	/* rebuild record */
 
+	if (errflg) {
+		update_ERRNO_int(errflg);
+		return;
+	}
+
 	f0 = fields_arr[0];
 
 	if (do_lint && (f0->flags & NULL_FIELD) != 0)
diff --git a/io.c b/io.c
index 1d15d887..b4688c89 100644
--- a/io.c
+++ b/io.c
@@ -718,6 +718,7 @@ redflags2str(int flags)
 		{ RED_PTY,	"RED_PTY" },
 		{ RED_SOCKET,	"RED_SOCKET" },
 		{ RED_TCP,	"RED_TCP" },
+		{ RED_NON_FATAL,	"RED_NON_FATAL" },
 		{ 0, NULL }
 	};
 
@@ -744,6 +745,8 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 	static struct redirect *save_rp = NULL;	/* hold onto rp that should
 	                                         * be freed for reuse
 	                                         */
+	bool is_output = false;
+	bool is_non_fatal = false;
 
 	if (do_sandbox)
 		fatal(_("redirection not allowed in sandbox mode"));
@@ -753,6 +756,7 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 		tflag = RED_APPEND;
 		/* FALL THROUGH */
 	case redirect_output:
+		is_output = true;
 		outflag = (RED_FILE|RED_WRITE);
 		tflag |= outflag;
 		if (redirtype == redirect_output)
@@ -761,6 +765,7 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 			what = ">>";
 		break;
 	case redirect_pipe:
+		is_output = true;
 		tflag = (RED_PIPE|RED_WRITE);
 		what = "|";
 		break;
@@ -773,6 +778,7 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 		what = "<";
 		break;
 	case redirect_twoway:
+		is_output = true;
 		tflag = (RED_READ|RED_WRITE|RED_TWOWAY);
 		what = "|&";
 		break;
@@ -794,6 +800,14 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 		lintwarn(_("filename `%s' for `%s' redirection may be result of logical expression"),
 				str, what);
 
+	/* input files/pipes are automatically nonfatal */
+	if (is_output) {
+		is_non_fatal = (in_PROCINFO("nonfatal", NULL, NULL) != NULL
+				|| in_PROCINFO(str, "nonfatal", NULL) != NULL);
+		if (is_non_fatal)
+			tflag |= RED_NON_FATAL;
+	}
+
 #ifdef HAVE_SOCKETS
 	/*
 	 * Use /inet4 to force IPv4, /inet6 to force IPv6, and plain
@@ -892,6 +906,12 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 			(void) flush_io();
 
 			os_restore_mode(fileno(stdin));
+			/*
+			 * Don't check is_non_fatal; see input pipe below.
+			 * Note that the failure happens upon failure to fork,
+			 * using a non-existant program will still succeed the
+			 * popen().
+			 */
 			if ((rp->output.fp = popen(str, binmode("w"))) == NULL)
 				fatal(_("can't open pipe `%s' for output (%s)"),
 						str, strerror(errno));
@@ -932,6 +952,10 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 					*errflg = errno;
 					/* do not free rp, saving it for reuse (save_rp = rp) */
 					return NULL;
+				} else if (is_non_fatal) {
+					*errflg = errno;
+					/* do not free rp, saving it for reuse (save_rp = rp) */
+					return NULL;
 				} else
 #endif
 					fatal(_("can't open two way pipe `%s' for input/output (%s)"),
@@ -1009,11 +1033,14 @@ redirect(NODE *redir_exp, int redirtype, int *errflg)
 				 * can return -1.  For output to file,
 				 * complain. The shell will complain on
 				 * a bad command to a pipe.
+				 *
+				 * 12/2014: Take nonfatal settings in PROCINFO into account.
 				 */
 				if (errflg != NULL)
 					*errflg = errno;
-				if (   redirtype == redirect_output
-				    || redirtype == redirect_append) {
+				if (! is_non_fatal &&
+				    (redirtype == redirect_output
+				     || redirtype == redirect_append)) {
 					/* multiple messages make life easier for translators */
 					if (*direction == 'f')
 						fatal(_("can't redirect from `%s' (%s)"),
@@ -3799,12 +3826,21 @@ in_PROCINFO(const char *pidx1, const char *pidx2, NODE **full_idx)
 	NODE *r, *sub = NULL; 
 	NODE *subsep = SUBSEP_node->var_value;
 
+	if (PROCINFO_node == NULL || (pidx1 == NULL && pidx2 == NULL))
+		return NULL;
+
 	/* full_idx is in+out parameter */
 
 	if (full_idx)
 		sub = *full_idx;
 
-	str_len = strlen(pidx1) + subsep->stlen	+ strlen(pidx2);
+	if (pidx1 != NULL && pidx2 == NULL)
+		str_len = strlen(pidx1);
+	else if (pidx1 == NULL && pidx2 != NULL)
+		str_len = strlen(pidx2);
+	else
+		str_len = strlen(pidx1) + subsep->stlen	+ strlen(pidx2);
+
 	if (sub == NULL) {
 		emalloc(str, char *, str_len + 1, "in_PROCINFO");
 		sub = make_str_node(str, str_len, ALREADY_MALLOCED);
@@ -3818,8 +3854,14 @@ in_PROCINFO(const char *pidx1, const char *pidx2, NODE **full_idx)
 		sub->stlen = str_len;
 	}
 
-	sprintf(sub->stptr, "%s%.*s%s", pidx1, (int)subsep->stlen,
-			subsep->stptr, pidx2);
+	if (pidx1 != NULL && pidx2 == NULL)
+		strcpy(sub->stptr, pidx1);
+	else if (pidx1 == NULL && pidx2 != NULL)
+		strcpy(sub->stptr, pidx2);
+	else
+		sprintf(sub->stptr, "%s%.*s%s", pidx1, (int)subsep->stlen,
+				subsep->stptr, pidx2);
+
 	r = in_array(PROCINFO_node, sub);
 	if (! full_idx)
 		unref(sub);