export vars from .env file

env.sh

#!/bin/bash

# Use grep to validate each line using regex (clears out comments, empty lines and validates that each line is in the format of env vars)
# Then send it out to sed, to append export at the beginning of each line and ; at the end
# Then eval all
eval "$(grep -E '^[A-Za-z_][A-Za-z0-9_]*=.*' '.env' | sed 's/.*/export &;/')"

#====================================================================================
# Archive
#====================================================================================
# Simple (Works for most cases)
export $(grep -v '^#' .env | xargs)
# Complex (Works with vars that contain spaces
eval "$(cat '.env' | grep -v '^#' | grep -v '^$' | sed 's/.*/export &;/')"
# Complex with 1 grep regex that covers all cases (comments, empty lines & validates the <var_name=...> style)
eval "$(cat './.env.local' | grep -E '^[A-Za-z_][A-Za-z0-9_]*=.*' | sed 's/.*/export &;/')"

#====================================================================================

example.env

# Example .env file

  
  
    
VAR=something
VAR2='one two three'

source_env_var_file

# Export all variables from a env var file
# $1 => env var file path
source_env_var_file() {
  file="$1"

  if [ ! -f "$file" ]; then
    echo "Error: $file does not exist"
    return 1
  fi

  while IFS= read -r line; do
    # Trim whitespace from start and end of line
    line=$(echo "$line" | sed 's/^[[:space:]]*//; s/[[:space:]]*$//')

    # Validate the line against the regex (skips empty lines and comments and lines where key is not valid)
    [[ ! "$line" =~ ^[A-Za-z_][A-Za-z0-9_]*=.* ]] && continue
    # # Skip empty lines
    # [ -z "$line" ] && continue
    # # Skip comments
    # [[ "$line" =~ ^#.*$ ]] && continue

    # Split the line into a key and value
    key=$(echo "$line" | cut -d "=" -f 1)
    value=$(echo "$line" | cut -d "=" -f 2-)

    # Trim whitespace from start and end of value
    value=$(echo "$value" | sed 's/^[[:space:]]*//; s/[[:space:]]*$//')

    # Skip if the key or value is empty
    [ -z "$key" ] || [ -z "$value" ] && continue

    # If the value isn't wrapped in quotes and contains any special characters, wrap it in single quotes
    if [[ "$value" != "'"* && "$value" != '"'* ]] && [[ "$value" =~ [[:space:]\!\@\#\$\%\^\&\*\(\)\[\]\{\}\<\>\?\!\~\`\:\;\+\=\-\.\/\\\|] ]]; then
      value="'$value'"
    fi

    # Export the variable
    export "$key"="$value"
  done <"$file"

  # # eval "$(grep -E '^export [A-Za-z_][A-Za-z0-9_]*=.*' "$file")" # validates lines with regex as (export key=value) and evals the line
  # eval "$(grep -E '^[A-Za-z_][A-Za-z0-9_]*=.*' "$file" | sed 's/.*/export &;/')" # normal approach - validate lines with regex as (key=value) and export them

  # Special chars to check: \s,!,@,#,$,%,^,&,*,(,),[,],{,},<,>,?,!,~,`,",',:,;,+,=,-,.,_,/,\,|
  # Wrap the value in single quotes if contains special chars and not already wrapped
  # eval "$(grep -E '^[A-Za-z_][A-Za-z0-9_]*=.*' "$file" | sed 's/^[[:space:]]*//; s/[[:space:]]*$//; s/[^A-Za-z0-9_]=/=/; s/.*/&;/; s/=[^'"'"'A-Za-z0-9_]/='\''&'\''/')"
}