Bash and other modern shell provides I/O redirection facility. There are 3 default standard files (standard streams) open:
1) stdin - Use to get input (keyboard) i.e. data going into a program.
2) stdout - Use to write information (screen)
3) stderr - Use to write error message (screen)
Understanding I/O streams numbers
The Unix / Linux standard I/O streams with numbers:Handle 0:
stdin Standard input
Handle 1:
stdout Standard output
Handle 2:
stderr Standard error
Redirecting the standard error (stderr) and stdout to file Use the following syntax:
$ command-name &>file
OR
$ command > file-name 2>&1
Another useful example:
# find /usr/home -name .profile 2>&1 | more