Add example to -r/--replace docs.

Fixes #308

2 files changed, 17 insertions, 0 deletions

diff --git a/doc/rg.1 b/doc/rg.1
index 5c21b0d9..95539939 100644
--- a/doc/rg.1
+++ b/doc/rg.1
@@ -340,6 +340,17 @@ Neither this flag nor any other flag will modify your files.
 .PP
 Capture group indices (e.g., $5) and names (e.g., $foo) are supported in
 the replacement string.
+.PP
+Note that the replacement by default replaces each match, and NOT the
+entire line.
+To replace the entire line, you should match the entire line.
+For example, to emit only the first phone numbers in each line:
+.IP
+.nf
+\f[C]
+rg\ \[aq]^.*([0\-9]{3}\-[0\-9]{3}\-[0\-9]{4}).*$\[aq]\ \-\-replace\ \[aq]$1\[aq]
+\f[]
+.fi
 .RE
 .TP
 .B \-s, \-\-case\-sensitive
diff --git a/doc/rg.1.md b/doc/rg.1.md
index 3ac61851..7f19cecf 100644
--- a/doc/rg.1.md
+++ b/doc/rg.1.md
@@ -231,6 +231,12 @@ Project home page: https://github.com/BurntSushi/ripgrep
     Capture group indices (e.g., $5) and names (e.g., $foo) are supported
     in the replacement string.
 
+    Note that the replacement by default replaces each match, and NOT the
+    entire line. To replace the entire line, you should match the entire line.
+    For example, to emit only the first phone numbers in each line:
+
+        rg '^.*([0-9]{3}-[0-9]{3}-[0-9]{4}).*$' --replace '$1'
+
 -s, --case-sensitive
 : Search case sensitively. This overrides --ignore-case and --smart-case.