From 7164d4196ace14a1acc9077a7a4d32e57131ff6e Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Mon, 23 Mar 2020 09:22:50 +0100
Subject: [PATCH v2] Document color support

Add a documentation appendix that explains the PG_COLOR and PG_COLORS
environment variables.
---
 doc/src/sgml/color.sgml    | 71 ++++++++++++++++++++++++++++++++++++++
 doc/src/sgml/filelist.sgml |  1 +
 doc/src/sgml/postgres.sgml |  1 +
 3 files changed, 73 insertions(+)
 create mode 100644 doc/src/sgml/color.sgml

diff --git a/doc/src/sgml/color.sgml b/doc/src/sgml/color.sgml
new file mode 100644
index 0000000000..c30b1942a5
--- /dev/null
+++ b/doc/src/sgml/color.sgml
@@ -0,0 +1,71 @@
+<!-- doc/src/sgml/color.sgml -->
+
+<appendix id="color">
+ <title>Color Support</title>
+
+ <indexterm zone="color">
+  <primary>color</primary>
+ </indexterm>
+
+ <para>
+  Most programs in the PostgreSQL package can produce colorized console
+  output.  This appendix describes how that is configured.
+ </para>
+
+ <sect1 id="color-when">
+  <title>When Color is Used</title>
+
+  <para>
+   To use colorized output, set the environment variable
+   <envar>PG_COLOR</envar><indexterm><primary>PG_COLOR</primary></indexterm>
+   as follows:
+
+   <orderedlist>
+    <listitem>
+     <para>
+      If the value is <literal>always</literal>, then color is used.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      If the value is <literal>auto</literal> and the standard error stream
+      is associated with a terminal device, then color is used.
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      Otherwise, color is not used.
+     </para>
+    </listitem>
+   </orderedlist>
+  </para>
+ </sect1>
+
+ <sect1 id="color-which">
+  <title>Configuring the Colors</title>
+
+  <para>
+   The actual colors to be used are configured using the environment variable
+   <envar>PG_COLORS</envar><indexterm><primary>PG_COLORS</primary></indexterm>
+   (note plural).  The value is a colon-separated list of
+   <literal><replaceable>key</replaceable>=<replaceable>value</replaceable></literal>
+   pairs.  The keys specify what the color is to be used for.  The values are
+   SGR (Select Graphic Rendition) specifications, which are interpreted by the
+   terminal.
+  </para>
+
+  <para>
+   The default value is <literal>error=01;31:warning=01;35:locus=01</literal>.
+  </para>
+
+  <tip>
+   <para>
+    This color specification format is also used by other software packages
+    such as <productname>GCC</productname>, <productname>GNU
+    coreutils</productname>, and <productname>GNU grep</productname>.
+   </para>
+  </tip>
+ </sect1>
+</appendix>
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 3da2365ea9..1043d0f7ab 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -170,6 +170,7 @@
 
 <!ENTITY limits     SYSTEM "limits.sgml">
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
+<!ENTITY color      SYSTEM "color.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index e59cba7997..1f7bd32878 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -278,6 +278,7 @@ <title>Appendixes</title>
   &docguide;
   &limits;
   &acronyms;
+  &color;
 
  </part>
 
-- 
2.25.0