bash cat write string to file code example

Example 1: bash string to file

# syntax (note: the -e switch is to allow for backslash escapes)
echo -e "<string-to-append>" >> <file-to-append-to>

# example 
echo -e "Hello there, new line!" >> RandomWorld.txt

# -----------------------------------------------
# In order to see the effect of -e, append the following string:
"Hello there,\n new line!"

Example 2: bash write stderr 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