diff options
Diffstat (limited to 'dla2img.sh')
| -rwxr-xr-x | dla2img.sh | 66 |
1 files changed, 52 insertions, 14 deletions
@@ -1,18 +1,35 @@ #!/bin/sh -# This script tested with bash 5.1, zsh 5.8, ksh 93u, and dash 0.5.11.4. -# If your environment doesn't have a shell compatible with one of those, -# I can't help you. +# This script deliberately written with old-school shell syntax, to +# support as many Bourne-like shells as possible. Do not complain that +# backticks are deprecated: this is supposed to (potentially) work +# on ancient shells that might exist on e.g. an Atari ST or Amiga. It +# *does* work on a wide variety of modern shells. -SELF="$(basename $0)" +# The only required external commands we call are magick, rm, and cat. +# If stat is present, it will be called (but no problem, if it's +# missing). + +# Tested with ImageMagick 7.1, but doesn't use any fancy features so +# it should work with any fairly recent ImageMagick. + +SELF="`basename $0`" # allow overriding magick path via environment. -MAGICK=${MAGICK:-magick} +if [ "$MAGICK" = "" ]; then + MAGICK="magick" +fi # only change this if the save file size changes in dla.xex. SIZE="256x170" -usage() { +# ...and if you change that, change this too: +FILESIZE="5440" + +INFILE="$1" +OUTFILE="$2" + +if [ -z "$INFILE" -o -z "$OUTFILE" -o "$INFILE" = "-h" -o "$INFILE" = "--help" ]; then cat <<EOF $SELF - convert saved files from dla.xex to image files. @@ -33,30 +50,51 @@ of supported arguments. See also: https://slackware.uk/~urchlay/repos/dla-asm EOF -} + exit 0 +fi -INFILE="$1" -OUTFILE="$2" +shift +shift -if [ -z "$INFILE" -o -z "$OUTFILE" -o "$INFILE" = "-h" -o "$INFILE" = "--help" ]; then - usage - exit 0 +if [ ! -e "$INFILE" ]; then + cat "$INFILE" > /dev/null # to get an error like "No such file or directory" + exit 1 fi -shift 2 +# if "stat" is missing, e.g. because we're on a non-GNU system that +# lacks the command, just skip the file size check (magick will error +# out instead; less user-friendly but no big deal). +if stat /dev/null >/dev/null 2>&1; then + if [ "`stat -L -c '%s' "$INFILE"`" != "$FILESIZE" ]; then + echo "$SELF: '$INFILE' not a DLA file (size != $FILESIZE)." 1>&2 + exit 1 + fi +fi + +rm -f "$OUTFILE" # do the conversion... if $OUTFILE has an unknown extension, we will # not get an error, and the conversion will succeed (the output will # just be a copy of the input!) -$MAGICK convert -size "$SIZE" -depth 1 "$@" gray:"$INFILE" "$OUTFILE" +# The "eval" is here to make this script work on the original Bourne +# shell (yes, the one from V7 UNIX). Seriously. Even with spaces +# in the arguments! +eval "$MAGICK convert -size '$SIZE' -depth 1 "$@" gray:'$INFILE' '$OUTFILE'" # if magick fails, exit with its error status (it already printed its # error messages to stderr). S="$?" if [ "$S" != "0" ]; then + echo "$SELF: conversion failed (invalid output file extension?)." 1>&2 exit "$S" fi +# if magick "succeeds" but the output file doesn't exist, complain. +if [ ! -e "$OUTFILE" ]; then + echo "$SELF: conversion failed (probably '$INFILE' is not a DLA) file)." 1>&2 + exit 1; +fi + # if magick "succeeds" but the output is identical to the input, let # the user know. if cmp "$INFILE" "$OUTFILE" >/dev/null 2>&1; then |