Task: Concatenate all .txt files residing in the /system tree into a single file "/system/folder3/temp/concat.txt"
Command: find /system -name "*.txt" -not -name "concat.txt" -print -exec cat {} \; > /system/folder3/temp/concat.txt
Equivalent command: find /system -type f -name "*.txt" -not -name "concat.txt" -print -exec cat {} \; > /system/folder3/temp/concat.txt