sbase/tail.1
Michael Forney ea8622a4ce tail: Process bytes with -c option, and add -m option for runes
POSIX says that -c specifies a number of bytes, not characters. This
flag is commonly used by scripts that operate on binary files to things
like extract a header. Treating the offsets as character offsets will
break things in mysterious ways.

Instead, add a -m option (chosen to match `wc -m`, which also operates
on characters) to handle character offsets.
2017-07-14 07:50:54 +02:00

54 lines
885 B
Groff

.Dd 2015-10-08
.Dt TAIL 1
.Os sbase
.Sh NAME
.Nm tail
.Nd display final lines of files
.Sh SYNOPSIS
.Nm
.Op Fl f
.Op Fl c Ar num | Fl m Ar num | Fl n Ar num | Fl Ns Ar num
.Op Ar file ...
.Sh DESCRIPTION
.Nm
writes the last 10 lines of each
.Ar file
to stdout. If no
.Ar file
is given,
.Nm
reads from stdin.
.Sh OPTIONS
.Bl -tag -width Ds
.It Fl c Ar num | Fl m Ar num | Fl n Ar num | Fl Ns Ar num
Display final
.Ar num
bytes | characters | lines |
lines. If
.Ar num
begins with '+'
it is an offset from the beginning of each
.Ar file .
If
.Ar num
begins with '-' it is as if no sign was given. The default is 10 lines.
.It Fl f
If one
.Ar file
is specified, append lines to output as
.Ar file
grows.
.El
.Sh SEE ALSO
.Xr head 1
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2013
specification.
.Pp
The
.Op Fl Ns Ar num
syntax is an extension to that specification.