FLORMAT - Format a string with named format variables
The function FLORMAT is used to easily insert a set of named
parameters into a string using simple format codes. The key point
is that format strings use named parameters instead of the
position in the string.
FLORMAT makes it easy to make maintainable and understandable
format codes. FLORMAT is a convenience routine, which will be most
suitable for formatting tabular output, but can be used for any
complicated string formatting job where the positional parameters
of STRING() become hard to manage. Users of Python will recognize
FLORMAT as implementing "string interpolation."
The user passes a format string similar to the IDL printf-style
format string (i.e. using modified "%" notation), and a set of
named fields either by passing a structure, keywords, or both. The
output strings are composed by inserting the named fields into the
format string with any requested formatting.
The function FLORMAT is equivalent to the STRING(...,FORMAT=fmt)
method of formatting a string, where the format string is allowed
to have the name of the variable.
For example consider formatting a time with hours, minutes
and seconds into a string as HH:MM:SS. One could use FLORMAT()
like this,
result = flormat('%(hour)02d:%(min)02d:%(sec)02d', $
hour=hour, min=min, sec=sec)
The variables HOUR, MIN and SEC are allowed to be scalars or
vectors. The key point here is that the format string contains the
named keyword variables (or structure entries). Unlike STRING(),
the actual variables can be passed in any order, since the format
string itself describes in what order the values will be assembled.
This is similar to string interpolation in Python.
The same variable can appear multiple times in the format string,
but the user only need to specify that variable once. For example,
result = flormat('<A="%(href)s">Download %(href)s</A>', $
href='filename.txt')
Note that HREF appears twice in the format string.
PRINTLOG - Captures a transcript of console output
PRINTLOG captures and archives a copy of any output sent to the
console. PRINTLOG is used exactly like PRINT and sends its output to
the screen as expected. However, it additionally saves a verbatim
copy of the output. This can be especially useful if an independent
session log is needed (like JOURNAL), or if a strict transaction
history is required. In order to use this procedure, you must change
your code to use PRINTLOG instead of PRINT, and maintain a string
variable which holds the log.
TRANSREAD - Read ASCII tables quickly and with ease
TRANSREAD parses an ASCII table into IDL variables, one variable
for each column in the table. The tabular data is not limited to
numerical values, and can be processed with an IDL FORMAT
expression.
TRANSREAD behaves similarly to READF/READS in that it transfers
ASCII input data into IDL variables. The difference is that
TRANSREAD reads more than one row in one pass, and returns data by
column. In a sense, it forms the transpose of the typical
output from READF or READS (which returns data by row), hence the
name TRANSREAD.
Feature highlights include:
- FORMAT expression is optionally accepted.
- Comment lines can optionally be recognized and ignored.
- Standalone operation. No other IDL procedures are needed.
- Input is either a file unit or a string array.
- Start and Stop "Cue" Phrases can be used to begin and end
the parsing operation.
- Extensive documentation is included in the header of
TRANSREAD.PRO itself.
PATHUTILS - Form relative and normalized file path names
The routines RELPATH and NORMPATH are used to construct relative
and normalized file system path names. RELPATH constructs a relative
path between two files or directories. For example, the relative path
from /path/to/directory/one to /path/to/file/two is ../../file/two.
NORMPATH normalizes a path so that the shortest possible path is
returned, and relative path components are removed if possible. For
example, the path /path/to/directory/one/../file/two can be normalized
to /path/to/file/two. If an absolute path is not possible, then the
shortest relative path is returned.
Both routines should be system independent, but have been tested on
Unix.
FXGPKG - Read and seek on pipes like normal files (Unix)
This is an embryonic library of routines which will read, write,
and seek on arbitrary Unix streams such as pipes and URLs. The most
important thing is the seek capability, which allows you to
address any point in the stream with random access rather than
sequential access.
At present, only Unix pipes are accessible. Eventually it is
desired to be able to read from generic URLs and shared memory using
third party such as CURL. The current implementation is to store the
contents of the Unix pipe in a temporary cache file. Unfortunately,
the input/output is limited to unformatted binary content.
All of the routines are required, and you may wish to download the
entire archive in one file as either a gzip'ed tar file or zip file.
The routines are internally documented, but you should probably
start with FXGOPEN.PRO.
|