bash script output and error to file
# Basic syntax:
command 2> error_file
# Note, in Bash and other Linux shells, when a program is executed, it
# uses one of three standard I/O streams. Each stream is represented
# by a numeric file descriptor:
# - 0, or stdin, the standard input stream
# - 1, or stdout, the standard output stream
# - 2, or stderr, the standard error stream
# By default the ">" operator uses 1 and is equivalent to "1>"
# Example uses:
# Redirect the standard error to a specific file:
command 2> error_file
# Redirect the standard output and standard error to different files:
command 1> output_file 2> error_file
# Redirect the standard output and standard error to the same file:
command &> output_and_error_file