iotests: Add poke_file_[bl]e functions

Similarly to peek_file_[bl]e, we may want to write binary integers into a file. Currently, this often means messing around with poke_file and raw binary strings. I hope these functions make it a bit more comfortable. Signed-off-by: Max Reitz <[email protected]> Code-suggested-by: Eric Blake <[email protected]> Message-Id: <[email protected]> Reviewed-by: Eric Blake <[email protected]> Signed-off-by: Max Reitz <[email protected]>
stefanha · Mar 26, 2020 · 2f8bb28 · 2f8bb28
1 parent 1656324
commit 2f8bb28
Showing 1 changed file with 24 additions and 0 deletions.
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
@@ -53,6 +53,30 @@ poke_file()
     printf "$3" | dd "of=$1" bs=1 "seek=$2" conv=notrunc &>/dev/null
 }
 
+# poke_file_le $img_filename $offset $byte_width $value
+# Example: poke_file_le "$TEST_IMG" 512 2 65534
+poke_file_le()
+{
+    local img=$1 ofs=$2 len=$3 val=$4 str=''
+
+    while ((len--)); do
+        str+=$(printf '\\x%02x' $((val & 0xff)))
+        val=$((val >> 8))
+    done
+
+    poke_file "$img" "$ofs" "$str"
+}
+
+# poke_file_be $img_filename $offset $byte_width $value
+# Example: poke_file_be "$TEST_IMG" 512 2 65279
+poke_file_be()
+{
+    local img=$1 ofs=$2 len=$3 val=$4
+    local str=$(printf "%0$((len * 2))x\n" $val | sed 's/\(..\)/\\x\1/g')
+
+    poke_file "$img" "$ofs" "$str"
+}
+
 # peek_file_le 'test.img' 512 2 => 65534
 peek_file_le()
 {