From: Diego Santa cruz <diego.santacruz@spinetix.com>
Date: Thu, 10 Oct 2024 10:45:34 +0000 (+0200)
Subject: dhcpcd: stdout output sometimes empty when redirected to a file (#364)
X-Git-Tag: v10.2.0~43
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=dc9cbc3e56b1e17f7c1a81a87a42b1f35470c71f;p=thirdparty%2Fdhcpcd.git

dhcpcd: stdout output sometimes empty when redirected to a file (#364)

Running dhpcd --dumplease with input from stdin and redirecting stdout
to a file outputs nothing to the output. The reason is that printf /
fprintf is used to write the output but it is not explicitly flushed
when done, or before exiting, and stdout to files is fully buffered by
default while stdout to terminals is line buffered by default.

This adds calls to fflush() at the end of dhcp_print_option_encoding()
and script_dump(), plus one just before exiting dhcpcd.

Signed-off-by: Diego Santa Cruz <diego.santacruz@spinetix.com>
---

diff --git a/src/dhcp-common.c b/src/dhcp-common.c
index 2130cb09..295ef74f 100644
--- a/src/dhcp-common.c
+++ b/src/dhcp-common.c
@@ -136,6 +136,7 @@ dhcp_print_option_encoding(const struct dhcp_opt *opt, int cols)
 	if (opt->type & OT_NOREQ)
 		printf(" norequest");
 	putchar('\n');
+	fflush(stdout);
 }
 
 struct dhcp_opt *
diff --git a/src/dhcpcd.c b/src/dhcpcd.c
index 654e1c0f..5fee26aa 100644
--- a/src/dhcpcd.c
+++ b/src/dhcpcd.c
@@ -2719,6 +2719,7 @@ exit1:
 	eloop_free(ctx.eloop);
 	logclose();
 	free(ctx.logfile);
+	fflush(stdout);
 	free(ctx.ctl_buf);
 #ifdef SETPROCTITLE_H
 	setproctitle_fini();
diff --git a/src/script.c b/src/script.c
index 4c71b8d0..3ee2eaa4 100644
--- a/src/script.c
+++ b/src/script.c
@@ -738,6 +738,7 @@ script_dump(const char *env, size_t len)
 			env += 4;
 		printf("%s\n", env);
 	}
+	fflush(stdout);
 	return 0;
 }