terminal-util: use getenv_bool for $SYSTEMD_COLORS

This changes the semantics a bit: before, SYSTEMD_COLORS= would be treated as
"yes", same as SYSTEMD_COLORS=xxx and SYSTEMD_COLORS=1, and only
SYSTEMD_COLORS=0 would be treated as "no". Now, only valid booleans are treated
as "yes". This actually matches how $SYSTEMD_COLORS was announced in NEWS.

diff --git a/man/systemd.xml b/man/systemd.xml
index 65f55199e2ace3882fd3248ef69beff398532045..e30333e2096cef0c256dd6f5a947921d61236e42 100644 (file)
--- a/man/systemd.xml
+++ b/man/systemd.xml
@@ -837,8 +837,10 @@
       <varlistentry>
         <term><varname>$SYSTEMD_COLORS</varname></term>
 
-        <listitem><para>Controls whether colorized output should be generated.
-        </para></listitem>
+        <listitem><para>The value must be a boolean. Controls whether colorized output should be
+        generated. This can be specified to override the decision that <command>systemd</command>
+        makes based on <varname>$TERM</varname> and what the console is connected to.</para>
+        </listitem>
       </varlistentry>
 
       <varlistentry>
@@ -849,7 +851,7 @@
         <listitem><para>Set by systemd for supervised processes during
         socket-based activation. See
         <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-        for more information. </para></listitem>
+        for more information.</para></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -858,7 +860,7 @@
         <listitem><para>Set by systemd for supervised processes for
         status and start-up completion notification. See
         <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-        for more information. </para></listitem>
+        for more information.</para></listitem>
       </varlistentry>
     </variablelist>
   </refsect1>

diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index 19d289275e20a575212b1127990d2baeeca88f2a..bfa936bd4e6e591a6c29211d221828b8244bd4bc 100644 (file)
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -39,6 +39,7 @@
 #include <unistd.h>
 
 #include "alloc-util.h"
+#include "env-util.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "fs-util.h"
@@ -1212,11 +1213,11 @@ bool colors_enabled(void) {
         static int enabled = -1;
 
         if (_unlikely_(enabled < 0)) {
-                const char *colors;
+                int val;
 
-                colors = getenv("SYSTEMD_COLORS");
-                if (colors)
-                        enabled = parse_boolean(colors) != 0;
+                val = getenv_bool("SYSTEMD_COLORS");
+                if (val >= 0)
+                        enabled = val;
                 else if (getpid() == 1)
                         /* PID1 outputs to the console without holding it open all the time */
                         enabled = !getenv_terminal_is_dumb();