# create a file name containing a backslash character \
file=${HOME}/Desktop/'te:st\file'.txt
echo "${file}"
echo "${file}" | sed -n -e 'l'

echo 'This is a test case for a file name containing a backslash \ character!' > "${file}"
open -e "${file}"

set -vx

# note: avoid trailing spaces in ed commands
cat <<EOF | /bin/ed -s "${file}"
H
,g|^This|s|test case|SUCCESSFUL TEST CASE|
w
EOF

open -e "${file}"


# escape backslashes
cat <<EOF | /bin/ed -s "${file//\\/\\\\}"
H
,g|^This|s|test case|SUCCESSFUL TEST CASE|
w
EOF

open -e "${file}"


# printf "%q"
help printf | sed -E "s/(%q)/$(printf '\e[1m\\1\e[m')/"
echo "${file}"
echo "$(printf "%q" "${file}")"   # cf. help printf
echo "$(printf "%q" "${file}")" | sed -n -e 'l'

# escape file name
cat <<EOF | /bin/ed -s "$(printf "%q" "${file}")"
H
,g|^This|s|backslash|BACKSLASH|
w
EOF

open -e "${file}"


echo "${file}"
echo "${file}" | sed -n -e 'l'

file="${file//\\/\\\\}"
echo "${file}"
echo "${file}" | sed -n -e 'l'


# references
man bash 2>/dev/null | less -p 'backslash'
man bash 2>/dev/null | less -p 'Each command in a pipeline'
man bash 2>/dev/null | less -p 'Functions are executed'
help printf | sed -E "s/(%q)/$(printf '\e[1m\\1\e[m')/"
open http://en.wikipedia.org/wiki/Filename


# "Each command in a pipeline is executed as a separate process (i.e., in a subshell)."
# From: man bash

# "Functions are executed in the context of the current shell; no new process is created to 
# interpret  them (contrast this with the execution of a shell script)."
# From: man bash

# "Unix-like systems are an exception, as the only control character forbidden in file names 
# is the null character, as that's the end-of-string indicator in C. Trivially, Unix also 
# excludes the path separator / from appearing in filenames."
# From: http://en.wikipedia.org/wiki/Filename