Scripts: Add zstd support to xzgrep.

Thanks to Adam Borowski.

src/scripts/xzgrep.1

@@ -6,7 +6,7 @@
 .\"
 .\" License: GNU GPLv2+
 .\"
-.TH XZGREP 1 "2011-03-19" "Tukaani" "XZ Utils"
+.TH XZGREP 1 "2020-12-05" "Tukaani" "XZ Utils"
 .SH NAME
 xzgrep \- search compressed files for a regular expression
 .SH SYNOPSIS
@@ -41,4 +41,5 @@
 .BR lzma (1),
 .BR gzip (1),
 .BR bzip2 (1),
+.BR lzop (1),
 or
@@ -44,5 +45,5 @@
 or
-.BR lzop (1).
+.BR zstd (1).
 All options specified are passed directly to
 .BR grep (1).
 .PP
@@ -54,4 +55,5 @@
 When reading from standard input,
 .BR gzip (1),
 .BR bzip2 (1),
+.BR lzop (1),
 and
@@ -57,5 +59,5 @@
 and
-.BR lzop (1)
+.BR zstd (1)
 compressed files are not supported.
 .PP
 If
@@ -94,4 +96,5 @@
 .BR gzip (1),
 .BR bzip2 (1),
 .BR lzop (1),
+.BR zstd (1),
 .BR zgrep (1)

src/scripts/xzgrep.in

@@ -159,6 +159,7 @@
     *[-.][zZ] | *_z | *[-.]gz | *.t[ag]z) uncompress="gzip -cdfq";;
     *[-.]bz2 | *[-.]tbz | *.tbz2) uncompress="bzip2 -cdfq";;
     *[-.]lzo | *[-.]tzo) uncompress="lzop -cdfq";;
+    *[-.]zst | *[-.]tzst) uncompress="zstd -cdfq";;
     *) uncompress="$xz -cdfq";;
   esac
   # Fail if xz or grep (or sed) fails.