hel1

unix v7是最后一个广泛发布的研究型UNIX版本

and minute.
Ranges are specifiable for each.
.sh AT
Schedule a one-shot action for an arbitrary time.
.sh TEE
Pass data between processes and divert a copy into one or more files.
.NH 2
Status Inquiries
.LP
.sh LS
List the names of one, several, or all files in one or more directories.
.op
Alphabetic or temporal sorting, up or down.
.op
Optional information:
size,
owner,
group,
date last modified,
date last accessed,
permissions,
i-node number.
.sh FILE
Try to determine 
what kind of information is in a file by consulting
the file system index and by reading the file itself.
.sh DATE
Print today's date and time.
Has considerable knowledge
of calendric and horological peculiarities.
.op
May set
.UC UNIX 's
idea of date and time.
.sh DF
Report amount of free space on file system devices.
.sh DU
Print a summary of total space occupied by all files in a hierarchy.
.sh QUOT
Print summary of file space usage by user id.
.sh WHO
Tell who's on the system.
.op
List of presently logged in users,
ports and times on.
.op
Optional history of all logins and logouts.
.sh PS
Report on active processes.
.op
List your own or everybody's processes.
.op
Tell what commands are being executed.
.op
Optional status information:
state and scheduling info,
priority,
attached terminal,
what it's waiting for,
size.
.sh IOSTAT
Print statistics about system I/O activity.
.sh TTY
Print name of your terminal.
.sh PWD
Print name of your working directory.
.NH 2
Backup and Maintenance
.LP
.sh MOUNT
Attach a device containing
a file system to
the tree of directories.
Protects against nonsense arrangements.
.sh UMOUNT
Remove the file system contained on a device
from the tree of directories.
Protects against removing a busy device.
.sh MKFS
Make a new file system on a device.
.sh MKNOD
Make an i-node (file system entry) for a special file.
Special files are
physical devices,
virtual devices, physical memory, etc.
.sh TP
.sh TAR
Manage file archives on magnetic tape or DECtape.
TAR is newer.
.op
Collect files into an archive.
.op
Update DECtape archive by date.
.op
Replace or delete DECtape files.
.op
Print table of contents.
.op
Retrieve from archive.
.sh DUMP
Dump the file system
stored on a specified device, selectively by date, or indiscriminately.
.sh RESTOR
Restore a dumped file system,
or selectively retrieve parts thereof.
.sh SU
Temporarily become the super user with all the rights and privileges
thereof.
Requires a password.
.sh DCHECK
.sh ICHECK
.sh NCHECK
Check consistency of file system.
.op
Print gross statistics:
number of files,
number of directories,
number of special files,
space used,
space free.
.op
Report duplicate use of space.
.op
Retrieve lost space.
.op
Report inaccessible files.
.op
Check consistency of directories.
.op
List names of all files.
.sh CLRI
Peremptorily expunge a file and its space from a file system.
Used to repair damaged file systems.
.sh SYNC
Force all outstanding I/O on the system to completion.
Used to shut down gracefully.
.NH 2
Accounting
.LP
The timing information on which the reports are based can be
manually cleared or shut off completely.
.sh AC
Publish cumulative connect time report.
.op
Connect time by user or by day.
.op
For all users or for selected users.
.sh SA
Publish Shell accounting
report.
Gives usage information on each command executed.
.op
Number of times used.
.op
Total system time, user time and elapsed time.
.op
Optional averages and percentages.
.op
Sorting on various fields.
.NH 2
Communication
.LP
.sh MAIL
Mail a message to one or more users.
Also used to read and dispose of incoming mail.
The presence of mail is announced by LOGIN
and optionally by SH.
.op
Each message can be disposed of individually.
.op
Messages can be saved in files or forwarded.
.sh CALENDAR
Automatic reminder service for events of today and tomorrow.
.sh WRITE
Establish direct terminal communication with another user.
.sh WALL
Write to all users.
.sh MESG
Inhibit receipt of messages from WRITE and WALL.
.sh CU
Call up another time-sharing system.
.OP
Transparent interface to remote machine.
.OP
File transmission.
.OP
Take remote input from local file or put remote output
into local file.
.OP
Remote system need not be
.UC UNIX .
.sh UUCP
.UC UNIX
to
.UC UNIX
copy.
.OP
Automatic queuing until line becomes available
and remote machine is up.
.OP
Copy between two remote machines.
.op
Differences, mail, etc., between two machines.
.NH 2
Basic Program Development Tools
.LP
Some of these utilities are used as integral parts of
the higher level languages described in section 2.
.sh AR
Maintain archives and libraries.
Combines several files into one for housekeeping efficiency.
.op
Create new archive.
.op
Update archive by date.
.op
Replace or delete files.
.op
Print table of contents.
.op
Retrieve from archive.
.sh AS
Assembler.
Similar to PAL-11, but different in detail.
.op
Creates object program consisting of
.in+2
.nf
code, possibly read-only,
initialized data or read-write code,
uninitialized data.
.in -2
.fi
.op
Relocatable object code is directly executable without
further transformation.
.op
Object code normally includes a symbol table.
.op
Multiple source files.
.op
Local labels.
.op
Conditional assembly.
.op
``Conditional jump'' instructions become
branches or branches plus jumps depending on distance.
.sh Library
The basic run-time library.
These routines are used freely by all software.
.op
Buffered character-by-character I/O.
.op
Formatted input and output conversion (SCANF and PRINTF)
for standard input and output, files, in-memory conversion.
.op
Storage allocator.
.op
Time conversions.
.op
Number conversions.
.op
Password encryption.
.op
Quicksort.
.op
Random number generator.
.op
Mathematical function library, including
trigonometric functions and inverses,
exponential, logarithm, square root,
bessel functions.
.sh ADB
Interactive debugger.
.op
Postmortem dumping.
.OP
Examination of arbitrary files, with no limit on size.
.op
Interactive breakpoint debugging with the debugger as a separate
process.
.OP
Symbolic reference to local and global variables.
.op
Stack trace for C programs.
.OP
Output formats:
.in+2
.nf
1-, 2-, or 4-byte integers in octal, decimal, or hex
.br
single and double floating point
.br
character and string
.br
disassembled machine instructions
.br
.fi
.in-2
.op
Patching.
.OP
Searching for integer, character, or floating patterns.
.OP
Handles separated instruction and data space.
.sh OD
Dump any file.
Output options include any combination of
octal or decimal by words,
octal by bytes,
ASCII,
opcodes,
hexadecimal.
.op
Range of dumping is controllable.
.sh LD
Link edit.
Combine relocatable object files.
Insert required routines from specified libraries.
.op
Resulting code may be sharable.
.op
Resulting code may have separate instruction and data spaces.
.sh LORDER
Places object file names in proper order for loading,
so that files depending on others come after them.
.sh NM
Print the namelist (symbol table) of an object program.
Provides control over the style and order of
names that are printed.
.sh SIZE
Report the core requirements
of one or more object files.
.sh STRIP
Remove the relocation and symbol table information from
an object file to save space.
.sh TIME
Run a command and report timing information on it.
.sh PROF
Construct a profile of time spent per routine
from statistics gathered by time-sampling the
execution of a program.
Uses floating point.
.op
Subroutine call frequency and average times for C programs.
.sh MAKE
Controls creation of large programs.
Uses a control file specifying source file dependencies
to make new version;
uses time last changed to deduce minimum amount of work necessary.
.op
Knows about CC, YACC, LEX, etc.
.NH 2
UNIX Programmer's Manual
.LP
.sh Manual
Machine-readable version of the
.UC UNIX
Programmer's Manual.
.op
System overview.
.op
All commands.
.op
All system calls.
.op
All subroutines in C and assembler libraries.
.op
All devices and other special files.
.op
Formats of file system and kinds
of files known to system software.
.op
Boot and maintenance procedures.
.sh MAN
Print specified manual section on your terminal.
.NH 2
Computer-Aided Instruction
.LP
.sh LEARN
A program for interpreting CAI scripts, plus scripts
for learning about 
.UC UNIX
by using it.
.op
Scripts for basic files and commands,
editor,
advanced files and commands,
.UC EQN ,
.UC MS
macros,
C programming language.