QMSG(1P) POSIX Programmer's Manual QMSG(1P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAMEqmsg — send message to batch jobs
SYNOPSISqmsg [−EO] message_string job_identifier...
DESCRIPTION
To send a message to a batch job is to request that a server write a
message string into one or more output files of the batch job. A mes‐
sage is sent to a batch job by a request to the batch server that man‐
ages the batch job. The qmsg utility is a user-accessible batch client
that requests the sending of messages to one or more batch jobs.
The qmsg utility shall write messages into the files of batch jobs by
sending a Job Message Request to the batch server that manages the
batch job. The qmsg utility shall not directly write the message into
the files of the batch job.
The qmsg utility shall send a Job Message Request for those batch jobs,
and only those batch jobs, for which a batch job_identifier is pre‐
sented to the utility.
The qmsg utility shall send Job Message Requests for batch jobs in the
order in which their batch job_identifiers are presented to the util‐
ity.
If the qmsg utility fails to process any batch job_identifier success‐
fully, the utility shall proceed to process the remaining batch
job_identifiers, if any.
The qmsg utility shall not exit before a Job Message Request has been
sent to the server that manages the batch job that corresponds to each
successfully processed batch job_identifier.
OPTIONS
The qmsg utility shall conform to the Base Definitions volume of
POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported by the implementation:
−E Specify that the message is written to the standard error of
each batch job.
The qmsg utility shall write the message into the standard
error of the batch job.
−O Specify that the message is written to the standard output of
each batch job.
The qmsg utility shall write the message into the standard
output of the batch job.
If neither the −O nor the −E option is presented to the qmsg utility,
the utility shall write the message into an implementation-defined
file. The conformance document for the implementation shall describe
the name and location of the implementation-defined file. If both the
−O and the −E options are presented to the qmsg utility, then the util‐
ity shall write the messages to both standard output and standard
error.
OPERANDS
The qmsg utility shall accept a minimum of two operands, message_string
and one or more batch job_identifiers.
The message_string operand shall be the string to be written to one or
more output files of the batch job followed by a <newline>. If the
string contains <blank> characters, then the application shall ensure
that the string is quoted. The message_string shall be encoded in the
portable character set (see the Base Definitions volume of
POSIX.1‐2008, Section 6.1, Portable Character Set).
All remaining operands are batch job_identifiers that conform to the
syntax for a batch job_identifier (see Section 3.3.1, Batch Job Identi‐
fier).
STDIN
Not used.
INPUT FILES
None.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of qmsg:
LANG Provide a default value for the internationalization vari‐
ables that are unset or null. (See the Base Definitions vol‐
ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
ables the precedence of internationalization variables used
to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of
all the other internationalization variables.
LC_CTYPE Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments).
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard
error.
LOGNAME Determine the login name of the user.
ASYNCHRONOUS EVENTS
Default.
STDOUT
None.
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
In addition to the default behavior, the qmsg utility shall not be
required to write a diagnostic message to standard error when the error
reply received from a batch server indicates that the batch job_identi‐
fier does not exist on the server. Whether or not the qmsg utility
waits to output the diagnostic message while attempting to locate the
job on other servers is implementation-defined.
The following sections are informative.
APPLICATION USAGE
None.
EXAMPLES
None.
RATIONALE
The qmsg utility allows users to write messages into the output files
of running jobs. Users, including operators and administrators, have a
number of occasions when they want to place messages in the output
files of a batch job. For example, if a disk that is being used by a
batch job is showing errors, the operator might note this in the stan‐
dard error stream of the batch job.
The options of the qmsg utility provide users with the means of placing
the message in the output stream of their choice. The default output
stream for the message—if the user does not designate an output stream—
is implementation-defined, since many implementations will provide, as
an extension to this volume of POSIX.1‐2008, a log file that shows the
history of utility execution.
If users wish to send a message to a set of jobs that meet a selection
criteria, the qselect utility can be used to acquire the appropriate
list of job identifiers.
The −E option allows users to place the message in the standard error
stream of the batch job.
The −O option allows users to place the message in the standard output
stream of the batch job.
Historically, the qmsg utility is an existing practice in the offerings
of one or more implementors of an NQS-derived batch system. The utility
has been found to be useful enough that it deserves to be included in
this volume of POSIX.1‐2008.
FUTURE DIRECTIONS
The qmsg utility may be removed in a future version.
SEE ALSO
Chapter 3, Batch Environment Services, qselect
The Base Definitions volume of POSIX.1‐2008, Section 6.1, Portable
Character Set, Chapter 8, Environment Variables, Section 12.2, Utility
Syntax Guidelines
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
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IEEE/The Open Group 2013 QMSG(1P)
