help [template]
template
A string listing the modules or packages for which help is desired.
Each list element may be a simple name or a pattern matching template.
Abbreviations are permitted. If template is omitted a long format
menu will be printed for the current package, listing each task (or
subpackage) and describing briefly what it is.
file_template = no
If this switch is set the template is interpreted as a filename matching
template, and all help blocks found in the named files are output. The help
database is not searched, hence manual pages can be printed or documents
may be formatted without entering the files into a help database.
In other words, "help file.hlp fi+" makes it possible to use help as
a conventional text formatter.
all = no
Print help for all help modules matching template, rather than only the
first one found.
parameter = all
If the value of this parameter is not "all", only the help text
for the given parameter will be printed.
section = all
If the value of this parameter is not "all", only the help text for the
given section (e.g. "usage", "description", "examples") will be printed.
option = help
The option parameter specifies the type of help desired, chosen from
the following:
.ls help
Print the full help block for the named module.
source
Print the source code for the module (which often contains additional
detailed comments).
sysdoc
Print the technical system documentation for the named module.
directory
Print a directory of all help blocks available for the named package.
alldoc
Print all help blocks in the file containing the help block for
the named procedure (i.e., both the user and system documentation).
files
Print the names of all help files associated with the named modules or
packages.
summary
Print only the titles and sizes of help blocks in referenced help files.
The contents of the blocks are skipped. Titles are printed for all
help blocks found in the file containing the help block for the named module.
.le
page = yes
Pause after every page of output text. Turning this off for large documents
speeds up output considerably.
nlpp = 59
The number of lines per page if output is redirected, e.g., to lprint.
lmargin = 1
Left margin on output.
rmargin = 72
Right margin on output.
helpdb = helpdb
The filename of the help database to be searched. If the value of the
parameter is the reserved string "helpdb", the actual filename is the value
of the CL environment variable helpdb.
device = terminal
Output device if the standard output is not redirected. If the value of
the parameter is the reserved string "terminal", the actual device name is
the value of the CL environment variable terminal. Only terminal
devices are permitted; help will not write directly to a printer device.
Despite the complex appearing hidden parameters, help is easy to use for simple tasks. Help is most commonly used to get help on the current package, and to get help on a program named in a CL menu. To get help on the current package one need only type help without any arguments. For example, if the current package is plot, the command and its output might appear as follows:
pl> help contour - Make a contour plot of an image graph - Graph one or more image sections or lists pcol - Plot a column of an image pcols - Plot the average of a range of image columns prow - Plot a line (row) of an image prows - Plot the average of a range of image lines surface - Make a surface plot of an image pl>
To get help on a module one supplies the module name as an argument,
pl> help graph
and the manual page for the plot.graph program will be printed on the terminal. To get a hardcopy of the manual page on the printer, the output may be redirected to the line printer, as follows:
pl> help graph | lprint
The function of the help program is to perform a depth first search of the help database helpdb, printing help for all packages and modules matching the template. By default the standard IRAF help database is searched, but any other help database may be searched if desired. A help database is precompiled with the mkhelpdb program to speed up runtime searches for help modules. The standard IRAF help database contains the documentation and source for all CL programs and system and math library procedures installed in IRAF.
A help template is a string type parameter to the CL. The form of a template is a list of patterns delimited by commas, i.e.,
"pattern1, pattern2, ..., patternN"
The form of a pattern is
package_pattern.module_pattern
If the "." is omitted module_pattern is assumed. The standard pattern matching metacharacters, i.e., "*?[]", are permitted in patterns. Simple patterns are assumed to be abbreviations.
1. Print the help text for the program delete in the package system (output will be directed to the terminal):
cl> help system.delete or cl> help delete or cl> help del
2. Print the help text on the line printer:
cl> help delete | lprint
3. Print help for the current package:
cl> help
4. Print the usage section of all modules in the package images:
cl> help images.* section=usage
5. Print a directory of all help blocks in the packages clpackage and clio (and any others whose names begin with the string "cl"):
cl> help cl* op=dir
6. Print a directory of each package in the database (useful for getting an overview of the contents of a help database):
cl> help * op=dir
7. Print the source for all of the string utilities in the system library package fmtio:
cl> help fmtio.str* op=source
8. Find all tasks that delete something:
cl> help * | match delete
9. Print the manual pages for the help and lprint tasks on the default printer device:
cl> help help,lprint | lpr
10. Capture the manual page for task hedit in a text file, in a form suitable for printing on any device.
cl> help hedit | type dev=text > hedit.txt
On some systems, typing the next command keystroke before the end-of-page prompt is printed may result in the character being echoed (messing up the output) and then ignored when raw mode is enabled for the prompt.
references, phelp, mkhelpdb, hdbexamine, mkmanpage, lroff,