Man page of looktxt
Section: USER COMMANDS (1)
Updated: May 29, 2009
Return to Main Contents
looktxt - Search and export numerics from any text/ascii file
[-b][-c][-f FORMAT][-H][-s SEC ...][-m META ...] file1 file2 ...
Extracting data from a text file is a never ending story. Usually, one will write a short script or program/function to analyse each specific input data format. The
command purpose is to read any text data file containing numerical blocks just as a human would read it. Specifically, it looks for contiguous numerical blocks, which are stored into matrices, and other parts of the input file are classified as
which are optionally exported. Numerical blocks are labelled according to the preceeding header block last word.
Blocks read from the data file can be sorted into sections. Each section
starts when it appears in a
and contains all following fields until a new section is found or the end of the file.
Additionally, one may search for specific metadata keywords, at user's choice. Each data field matching the keyword metadata
will create a new entry in the
The output data files may be generated using "Matlab", "Scilab", "IDL", "Octave", "XML", "HTML", and "Raw" formats (using the -f FORMAT option), using a structure-like hierarchy. This hierarchy contains all
that have been found during the parsing of the input data file.
the data is simply loaded into memory using e.g. 'matlab> ans=foo;'. The exact method to import data is indicated at the begining of the output data file, and depends on the format.
The command can handle large files (tens of Mb) within a few secconds, with minimal memory requirements.
- -h | --help
displays the command help
- -b | --binary
sets binary mode for large numerical blocks (more than 100 elements). This option creates an additional '.bin' file to be read accordingly to the references indicated for each field in the output text data file. This is transparently done when reading output files with matlab(1), scilab(1), idl(1), and octave(1).
- -c | --catenate
Catenates similar numerical fields (which have similar dimensions and names)
- -F | --force
Overwrites existing files
- -f FORMAT | --format=FORMAT
Sets the output format for generated files
- --fortran | --wrapped
Catenates single wrapped output lines with previous matrices (e.g. caused by the 80 chars per line limit in old data formats written by fortran codes)
- -H | --headers
for each numerical field (recommended)
- -s SEC | --section=SEC ...
Classifies fields into
matching word SEC. This option can be repeated
- -m META | --metadata=META ...
Extracts lines containing word META as user
This option can be repeated
The command supports other options which are listed using
Among these are
When numerical data blocks only use isspace(3) separators (\n \r \f \t \v and space), the reading can be made faster with even lower memory requirements.
Silent mode, to only display fatal errors
- --verbose | -v | --debug
To display plenty of informations
- --makerows=NAME ...
When a numerical data block label matching NAME is found, it is transformed into a row vector. This may be used for wrapped files (--fortran option). This option can be repeated
- - o FILE | --outfile=FILE
to use FILE as output file. The streams
may be used, but we then recommend to specifiy the --silent option to avoid unwanted messages in the output.
- Typical usage (exporting headers as well)
- For large data files (using binary float storage, catenate and fortran mode)
-F -c -H -b --fortran foo
- Sorting data into sections, and searching a metadata keyword
-s SEC1 -s SEC2 -m META1 -H
will result in the following Matlab structure:
Creator: 'Looktxt 1.0.6 29 May 2009 Farhi E. [farhi at ill.fr]'
User: 'farhi on localhost'
Date: 'Fri Dec 12 11:35:20 CET 2008'
Command: [1x195 char]
Headers: struct SEC1, struct SEC2, struct MetaData (headers)
Data: struct SEC1, struct SEC2, struct MetaData (numerics)
- Some options that may be used for specific data formats:
- ILL ASCII data format:
--headers --fortran --catenate --fast --binary --makerows=FFFF --makerows=JJJJ --makerows=IIII
- ILL TAS ASCII data format:
--headers --section=PARAM --section=VARIA --section=ZEROS --section=POLAN --metadata=DATA
- SPEC data file (ESRF, X-rays...):
--headers --metadata="#S " --comment=
environment variable may be set to define the default export format. When not defined, the Matlab format is used as default.
The command by itself should work properly. In case of trouble, you may have more information with the --verbose or --debug options. Most problems arise when importing data after running looktxt. E.g. these come from idl(1) and scilab(1) limitations (lines too long, too many structure elements, ...). The --binary may solve some of these import issues.
In case of memory allocation problems, you may try the --fast option.
looktxt returns -1 in case of error, 0 when no file was processed, or the number of processed files.
Usual procedure: ./configure; make; make install. An installer is available using
which may be used both from Linux/Unix and Windows systems. In principle, the
only required file is the executable
, to be copied in a system executable location, e.g. '/usr/local/bin', '/usr/bin', or 'c:\windows\system32'.
Binaries are pre-compiled for usual systems with the package.
Emmanuel FARHI (farhi (at) ill.eu) and the Institut Laue Langevin at http://www.ill.eu
matlab(1), idl(1), scilab(1), octave(1), xmlcatalog(1), html2text(1)
- OTHER OPTIONS
- EXIT STATUS
- SEE ALSO
This document was created by
using the manual pages.
Time: 07:50:58 GMT, May 29, 2009