Bash gnu

Replacements

#!/bin/bash
input="I love Suzi and Marry"
replacement="Sara"
echo "${input/Suzi/$replacement}"
# 'I love Sara and Marry'

# To replace all occurrences, use ${parameter//pattern/string}:

Loop over lines instead of words

Source (stackoverflow)

OIFS="$IFS" # Save old field separator
IFS=$'\n'   # Now set it to newline
for file in $(find . -type f -name "*.csv"); do
    echo "file = $file"
    diff "$file" "/some/other/path/$file"
    read line
done
IFS="$OIFS"

Fish

Evaluated variables (functions, abbreviations) are stored in ~/.config/fish/fish_variables.