- Added -D option to backtick

 - Doc updated

1 files changed, 8 insertions, 4 deletions

diff --git a/doc/backtick.html b/doc/backtick.html
index 7bdc037..bdcd785 100644
--- a/doc/backtick.html
+++ b/doc/backtick.html
@@ -29,7 +29,7 @@ another program.
 </p>
 
 <pre>
-     backtick [ -i ] [ -n ] <em>variable</em> { <em>prog1...</em> } <em>prog2...</em>
+     backtick [ -i | -D <em>default</em> ] [ -n ] <em>variable</em> { <em>prog1...</em> } <em>prog2...</em>
 </pre>
 
 <ul>
@@ -45,9 +45,13 @@ output as a value. </li>
 <h2> Options </h2>
 
 <ul>
- <li> <tt>-i</tt>&nbsp;: insist. If <em>prog1</em> exits non-zero,
+ <li> <tt>-i</tt>&nbsp;: insist. If <em>prog1</em> crashes or exits non-zero,
 <tt>backtick</tt> exits with the same exit code (or 111 if <em>prog1</em>
-crashed for some reason). Without this option, <tt>backtick</tt> execs into
+crashed). </li>
+ <li> <tt>-D&nbsp;<em>default</em></tt>&nbsp;: default value. If
+<em>prog1</em> crashes or exits non-zero, <em>default</em> is used as
+<em>variable</em>'s value. If neither the <tt>-i</tt> nor the <tt>-D</tt>
+option have been given, <tt>backtick</tt> execs into
 <em>prog2...</em> no matter what <em>prog1</em> does, with the null word as
 <em>variable</em>'s value if <em>prog1</em> didn't write anything before
 dying. </li>
@@ -58,7 +62,7 @@ output. </li>
 <h2> Notes </h2>
 
 <ul>
- <li> You can start <em>prog2...</em> with "import <em>variable</em> unexport <em>variable</em>"
+ <li> You can start <em>prog2...</em> with "import -u <em>variable</em>"
 to perform variable substitution. </li>
 </ul>