Merge pull request #3 from Samueru-sama/main

add POSIX script to get offset of AppImage

Author: fiftydinar

get_appimage_offset

@@ -0,0 +1,54 @@
+#!/bin/sh
+
+export LC_ALL=C
+offset="$(od -An -vtx1 -N 64 -- "$1" | awk '
+	BEGIN {
+		for (i = 0; i < 16; i++) {
+			c = sprintf("%x", i)
+			H[c] = i
+			H[toupper(c)] = i
+		}
+	}
+	{
+		elfHeader = elfHeader " " $0
+	}
+	END {
+		$0 = toupper(elfHeader)
+		if ($5 == "02") is64 = 1; else is64 = 0
+		if ($6 == "02") isBE = 1; else isBE = 0
+		if (is64) {
+			if (isBE) {
+				shoff = $41 $42 $43 $44 $45 $46 $47 $48
+				shentsize = $59 $60
+				shnum = $61 $62
+			} else {
+				shoff = $48 $47 $46 $45 $44 $43 $42 $41
+				shentsize = $60 $59
+				shnum = $62 $61
+			}
+			} else {
+			if (isBE) {
+				shoff = $33 $34 $35 $36
+				shentsize = $47 $48
+				shnum = $49 $50
+			} else {
+				shoff = $36 $35 $34 $33
+				shentsize = $48 $47
+				shnum = $50 $49
+			}
+		}
+		print parsehex(shoff) + parsehex(shentsize) * parsehex(shnum)
+	}
+	function parsehex(v, i, r) {
+		r = 0
+		for (i = 1; i <= length(v); i++)
+			r = r * 16 + H[substr(v, i, 1)]
+		return r
+	}'
+)"
+
+if [ -n "$offset" ]; then
+	echo "$offset"
+else
+	exit 1
+fi

make-appimage.sh

@@ -39,5 +39,12 @@ quick-sharun /usr/bin/gearlever \
 sed -i '/^pkgdatadir/c\pkgdatadir = os.getenv("SHARUN_DIR", "/usr") + "/share/gearlever"' ./AppDir/bin/gearlever
 sed -i '/^localedir/c\localedir = os.getenv("SHARUN_DIR", "/usr") + "/share/locale"' ./AppDir/bin/gearlever
 
+# Gear lever uses a bash script to get offset that depends on readelf
+# Replace it for a POSIX alternative that does not need bash
+cp -v ./get_appimage_offset ./AppDir/lib/gearlever
+chmod +x ./AppDir/lib/gearlever/get_appimage_offset
+rm -f ./AppDir/bin/get_appimage_offset
+
 # Turn AppDir into AppImage
 quick-sharun --make-appimage
+