Update documentation and adjust blocksize if larger than the device size

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 26 insertions, 1 deletions

diff --git a/deadshred.1 b/deadshred.1
index 5c3eb63..e445c05 100644
--- a/deadshred.1
+++ b/deadshred.1
@@ -4,6 +4,8 @@ deadshred \- override the contents of a device that may be broken
 
 .SH SYNOPSIS
 .B deadshred
+[-b
+.IR blocksize ]
 [-o
 .IR offset ]
 [-l
@@ -11,6 +13,7 @@ deadshred \- override the contents of a device that may be broken
 |
 -e
 .IR postend ]
+[-r]
 .I device
 [<
 .IR random-source ]
@@ -29,6 +32,10 @@ to override and retries it later.
 .SH OPTIONS
 The following options are supported:
 .TP
+.BR -b \ \fIblocksize\fP
+Selects the initial block-size for writing on the
+first pass over the device.
+.TP
 .BR -e \ \fIpostend\fP
 Position in the
 .I device
@@ -56,9 +63,13 @@ bytes past
 The index of the first byte in the
 .I device
 to overwrite.
+.TP
+.B -r
+Start writing from the end instead of from the
+beginning on the first pass over the device.
 .PP
 The value of the
-.B -elo
+.B -belo
 flags can be expressed a sum of terms (delimited by
 SP
 .RB (' " " '),
@@ -95,6 +106,20 @@ Unless the standard input is a terminal device, it shall be an
 unless source of either random data or a particular byte to
 fill the device with.
 
+.SH STDOUT
+If the process is terminated using either of the signals
+SIGTERM or SIGINT, the process will write to standard output
+a map of sections that has not been overwritten yet. The
+output will be the concatenation of one string per section,
+each on the format
+.PP
+.nf
+\fB\(dq%s%x-%x/%x\(dq,\fP <\fB\(dq0x\(dq\fP for the first section, \fB\(dq,\(dq\fP otherwise>\fB,\fP
+              <\fIindex of the first byte in the section\fP>\fB,\fP
+              <\fIindex of the byte after the last in the section\fP>\fB,\fP
+              <\fIthe block size that should be used when trying to overwrite\fP>
+.fi
+
 .SH NOTES
 While the
 .B deadshred