IMGSIZER(1) Web Tools IMGSIZER(1)NAMEimgsizer - automatically splice in height and width params for HTML IMG
tags
SYNOPSISimgsizer [-d file] [--document-root file] [-h file] [--help file] [-n]
[--no-overwrite] [HTMLFile] [-v file] [--version]
OPTIONS
Display version information and exit.
Display usage information.
Directory where absolute image filenames (i.e, ones which contain a
leading "/") may be found.
-n, --no-overwwrite, .SH DESCRIPTION
The imgsizer script automates away the tedious task of creating and
updating the extension HEIGHT and WIDTH parameters in HTML IMG
tags. These parameters help many browsers (including the
Netscape/Mozilla family) to multi-thread image loading, instead of
having to load images in strict sequence in order to have each
one's dimensions available so the next can be placed. This
generally allows text on the remainder of the page to load much
faster.
This script will try create such attributes for any IMG tag that lacks
them. It will correct existing HEIGHT and WIDTH tags unless either
contains a percent (%) sign, in which case the existing dimensions are
presumed to be relative and left unaltered.
This script may be called with no arguments. In this mode, it filters
HTML presented on stdin to HTML (unaltered except for added or
corrected HEIGHT and WIDTH attributes) on stdout. If called with file
arguments, it will attempt to transform each file in place. Each
argument file is not actually modified until the script completes a
successful conversion pass.
The -d <directory> option sets the DocumentRoot, where images with an
absolute filename (i.e., ones which contain a leading "/") may be
found. If none is specified, the DocumentRoot defaults to the current
working directory.
The -n (no-overwrite) opion prevents the program from overwriting
existing width and height tags if both are present.
Additional options may also be specified in the environmental variable
"IMGSIZER". For example, to avoid typing "imgsizer -d /var/www/docs"
each time imgsizer is invoked, you might tell sh (or one of its
descendants):
IMGSIZER="-d /var/www/docs"; export IMGSIZER
or, if you use csh:
setenv IMGSIZER "-d /var/www/docs"
This script is written in Python, and thus requires a Python
interpreter on the host system. It also requires either the identify(1)
utility distributed in the open-source ImageMagick suite of
image-display and manipulation tools, or a modern version of file(1)
and rdjpgcom(1). These utilities are used to extract sizes from the
images; imgsizer itself has no knowledge of graphics formats. The
script will handle any image format known to identify(1) including PNG,
GIF, JPEG, XBM, XPM, PostScript, BMP, TIFF, and anything else even
remotely likely to show up as an inline image.
NOTE
The -q, -l, and -m options of the 1.0 versions are gone. What they used
to do has been made unnecessary by smarter logic.
BUGS
The code uses regular expressions rather than true HTML/XML parsing.
Some perverse but legal constructions, like extraneous space within
quoted numeric attributes, will be mangled.
AUTHOR
Originally created by Eric S. Raymond <esr@thyrsus.com>. Additional
code contributed by Erik Rossen, Michael C. Toren <michael@toren.net>,
and others. For updates, see <http://www.catb.org/~esr>
SEE ALSOidentify(1), file(1), rdjpgcom(1).
imgsizer 04/05/2015 IMGSIZER(1)
