add Porting/p4d2p

p4raw-id: //depot/perl@1485

1 files changed, 84 insertions, 0 deletions

diff --git a/Porting/p4d2p b/Porting/p4d2p
new file mode 100755
index 0000000000..67780a9393
--- /dev/null
+++ b/Porting/p4d2p
@@ -0,0 +1,84 @@
+#!/l/local/bin/perl -wspi.bak
+
+#
+# reads a perforce style diff on stdin and outputs appropriate headers
+# so the diff can be applied with the patch program
+#
+# Gurusamy Sarathy <gsar@umich.edu>
+#
+
+BEGIN {
+    $0 =~ s|.*/||;
+    if ($h or $help) {
+	print STDERR <<USAGE;
+Usage: $0 [-v] [-h] files
+
+	-h	print this help
+	-v	output progress messages
+
+Does inplace edit of diff files output by the perforce commands
+"p4 describe", "p4 diff", and "p4 diff2". The result is suitable
+for feeding to the "patch" program.
+
+If no files are specified, reads from stdin and writes to stdout.
+
+WARNING: It only handles context or unified diffs.
+
+Example: p4 describe -du 123 | $0 > change-123.patch
+
+USAGE
+	exit(0);
+    }
+    unless (@ARGV) { @ARGV = '-'; undef $^I; }
+    use vars qw($thisfile $time $file $fnum $v $h $help);
+    $thisfile = "";
+    $time = localtime(time);
+}
+
+my ($cur, $match);
+$cur = m<^==== //depot/(.+?)\#\d+.* ====$> ... m<^(\@\@.+\@\@|\*+)$>;
+
+$match = $1;
+
+if ($ARGV ne $thisfile) {
+    warn "processing patchfile [$ARGV]\n" unless $ARGV eq '-';
+    $thisfile = $ARGV;
+}
+
+# while we are within range
+if ($cur) {
+    # set the file name after first line
+    if ($cur == 1) {
+	$file = $match;
+	$fnum++;
+    }
+    # emit the diff header when we hit last line
+    elsif ($cur =~ /E0$/) {
+	my $f = $file;
+
+	# special hack for perl so we can always use "patch -p1"
+	$f =~ s<^.*?(perl.*?/)><$1>;
+
+	# unified diff
+	if ($match =~ /^\@/) {
+	    warn "emitting udiff header\n" if $v;
+	    $_ = "Index: $f\n--- $f.~1~\t$time\n+++ $f\t$time\n$_";
+	}
+	# context diff
+	elsif ($match =~ /^\*/) {
+	    warn "emitting cdiff header\n" if $v;
+	    $_ = "Index: $f\n*** $f.~1~\t$time\n--- $f\t$time\n$_";
+	}
+    }
+    # see if we hit another patch (i.e. previous patch was empty)
+    elsif (m<^==== //depot/(.+?)\#\d+.* ====$>) {
+	$file = $match = $1;
+    }
+    # suppress all other lines in the header
+    else {
+	$_ = "";
+    }
+    warn "file [$file] line [$cur] file# [$fnum]\n" if $v;
+}
+
+$_ .= "End of Patch.\n" if eof;