find a file containing some text

TL;DW

# find with grep
# + concatinates results and runs the command once, faster
find . -name "*.txt" -exec grep -l "somename" '{}' '+'

# run a command for each result individually
find . -name "*.txt" -exec basename '{}' \';' |  column

# case insensitive
find -iname "SoMeNaMe.TxT

# file or dir
find -type f
find -type d

# define file owner
find -user Bob

# define file group
find -group wheel

# by permission
find -perm 777

# find by size
find -size +1G