mirror of
https://github.com/GnoConsortium/gno.git
synced 2024-11-18 19:09:31 +00:00
131 lines
3.8 KiB
Groff
131 lines
3.8 KiB
Groff
.TH DSORT 1 "Commands and Applications" "14 June 1994" "Version 1.0"
|
|
.SH NAME
|
|
dsort, msort \- sort text files lexicographically
|
|
.SH SYNOPSIS
|
|
.B msort
|
|
[
|
|
.I -hvV?
|
|
] [
|
|
.I "-o outfile"
|
|
] [
|
|
.I "-n lines"
|
|
]
|
|
.I file1
|
|
[
|
|
.I "file2 ..."
|
|
]
|
|
.LP
|
|
.B dsort
|
|
[
|
|
.I -hvV?
|
|
] [
|
|
.I "-l length"
|
|
] [
|
|
.I "-n lines"
|
|
] [
|
|
.I "-o outfile"
|
|
] [\fI-t path1\fR[,\fIpath2\fR[,\fIpath3\fR[,\fIpath4\fR]]]] \fIinfile\fR
|
|
.SH DESCRIPTION
|
|
.BR dsort " and " msort
|
|
are robust text file sorting utilities. While they do not support a lot
|
|
of features, they are designed to sort large (and small) files very quickly.
|
|
.LP
|
|
.B msort
|
|
is an in-place memory sort. Since it uses the heapsort algorithm, it is
|
|
O[n lg n] both on average and for worst-case. Provided it has enough memory,
|
|
.BR msort
|
|
will sort files with lines of arbitrary length. Unless overridden by the
|
|
.I -n
|
|
flag,
|
|
.BR msort
|
|
will sort files of up to 1000 lines. Larger files can be sorted provided
|
|
there is sufficient core memory. If multiple input files are given, the
|
|
output is the concatenated result of sorting the input files separately.
|
|
Thus, the following would be equivalent:
|
|
.LP
|
|
.nf
|
|
% msort file1 file2 file3 >outfile
|
|
and
|
|
% msort file1 >file1out
|
|
% msort file2 >file2out
|
|
% cat file1out file2out >outfile
|
|
.fi
|
|
.LP
|
|
.B dsort
|
|
is a disk sort intended for files too large to be sorted in memory. It
|
|
uses a four-file polyphase merge algorithm. Since it is an I/O-bound
|
|
program,
|
|
.BR dsort "'s
|
|
speed is very dependant on the speed of the device used for temporary files.
|
|
By default,
|
|
.BR dsort
|
|
will sort files with lines up to 512 characters long. Lines with more
|
|
characters will be trucated unless the
|
|
.I -l
|
|
flag is used. Also by default, 1000 lines at a time will be sorted in
|
|
memory during the collection (first) phase of the merge sort algorithm.
|
|
This can be changed using the
|
|
.I -n
|
|
flag.
|
|
.BR dsort
|
|
will accept only one input file.
|
|
.LP
|
|
Both
|
|
.BR dsort " and " msort
|
|
leave the input file(s) intact.
|
|
.SH OPTIONS
|
|
.nf
|
|
\fI-h\fR \fI-?\fR -- print version and usage info, then exit
|
|
\fI-l\fR \fIlength\fR -- use a line length of \fIlength\fR
|
|
\fI-n\fR \fIlines\fR -- sort \fIlines\fR lines in memory, (for \fBdsort\fR); don't
|
|
try to sort files over \fIlines\fR long (for \fBmsort\fR).
|
|
\fI-o\fR \fIoutfile\fR -- send sorted output to \fIoutfile\fR rather than to stdout
|
|
\fI-t\fR \fIpathlist\fR -- use \fIpathlist\fR as the locations of temp files. If any
|
|
of these are not specified, dsort will attempt to use
|
|
the directory specified by the environment variable
|
|
$(TMPDIR), then the system default temp path.
|
|
\fI-v\fR -- verbose operation
|
|
\fI-V\fR -- print version information
|
|
.fi
|
|
.SH HINTS
|
|
If you have more than one fast drive, the speed of
|
|
.B dsort
|
|
can in general be improved by using four different drives for the
|
|
path list when using
|
|
.I -t .
|
|
The best speed observed, however, has occurred when $(TMPDIR) or /tmp
|
|
reside on a RAM disk or ROM disk.
|
|
It is not suggested that floppies be used for temporary files.
|
|
.SH RESOURCE USAGE
|
|
Both
|
|
.BR dsort " and " msort
|
|
use 1k of stack space.
|
|
.LP
|
|
.BR msort
|
|
is an in-place sort, so in general the amount of core memory used is
|
|
the same as the size of the file to be sorted. When sorting multiple
|
|
files,
|
|
.BR msort "'s
|
|
memory usage will match the size of the largest input file, not the
|
|
total of all files. It will use a minimum of approximately 4k of core
|
|
memory.
|
|
.LP
|
|
.BR dsort
|
|
by default uses approximately 512k of core memory. This can be modified
|
|
by changing the
|
|
.I -l
|
|
and
|
|
.I -n
|
|
parameters. Core memory usage is approximately the product of these two
|
|
parameters.
|
|
.LP
|
|
When using
|
|
.BR dsort ,
|
|
the amount free space on the temporary path(s) must be at least twice
|
|
the size of the file to be sorted.
|
|
.SH AUTHOR
|
|
Devin Reade \- glyn@cs.ualberta.ca
|
|
.SH SEE ALSO
|
|
.BR sort (1),
|
|
.BR uniq (1).
|