Bash:
Об'єднання рядків
How to: (Як це робити:)
Bash lets you concatenate strings easily. Here are some straightforward examples:
# Direct concatenation
greeting="Hello, "
name="Oleksiy"
welcome_message=$greeting$name
echo $welcome_message
# Output: Hello, Oleksiy
# Using curly braces for clarity
full_greeting="${greeting}there, ${name}!"
echo $full_greeting
# Output: Hello, there, Oleksiy!
# Concatenating with a variable update
suffix=" How are you?"
welcome_message+=$suffix
echo $welcome_message
# Output: Hello, Oleksiy How are you?Deep Dive (Занурення глибше):
In early computer programming, memory was precious. Concatenating strings had to be done carefully. Today’s Bash doesn’t sweat the small stuff - it’s easy and efficient.
Alternatives to Bash’s direct string concatenation include using printf, echo, or command substitution:
# Using printf
printf -v full_message "%s%s" "$greeting" "$name"
echo $full_message
# Output: Hello, Oleksiy
# Concatenation with command substitution
date_prefix=$(date +"%Y-%m-%d")
log_message="Log entry for $date_prefix: All is well."
echo $log_message
# Output: Log entry for 2023-03-15: All is well.Behind the scenes, Bash handles string concatenation by simply laying one string after another in memory, letting you treat multiple strings as one.