Bash脚本实现仅输出非空行且不使用行变量的方法

Got it, let's tweak your script to skip empty lines while keeping your existing field-processing logic intact—no need for a separate variable to hold each full line. Here are two clean, straightforward approaches:

Option 1: Pre-Filter Empty Lines with grep #

Use grep -v '^$' to strip out empty lines before feeding the file into your read loop. This keeps your loop logic simple since you only process non-empty lines right from the start.

Here's the modified script:

while IFS=: read -r name class; do
    # Keep your existing formatting logic here (adjust the echo to match your needs)
    echo "Name: $name | Class: $class"
done < <(grep -v '^$' /home/user/scripte/schuelerListe.txt)

• The <(...) syntax is process substitution—it lets us pass the filtered output of grep directly to the loop without spawning a subshell (useful if you ever need to modify variables inside the loop later).
• grep -v '^$' targets lines that are NOT (-v) empty (^$ means start-of-line to end-of-line with nothing in between).

Option 2: Skip Empty Lines Inside the Loop #

If you prefer not to use an extra grep process, add a quick check inside the loop to skip lines where both fields are empty (which is exactly what happens when reading a blank line):

while IFS=: read -r name class; do
    # Skip lines where both name and class are empty (i.e., empty lines)
    [[ -z "$name" && -z "$class" ]] && continue
    
    # Your existing formatting logic stays here
    echo "Name: $name | Class: $class"
done < /home/user/scripte/schuelerListe.txt

• [[ -z "$var" ]] checks if a variable is empty. Since a blank line sets both name and class to empty strings, this condition catches those lines and skips them with continue.

Example Output #

If your schuelerListe.txt looks like this:

Lena:10C
Jonas:9B

Mia:11A

Both scripts will output:

Name: Lena | Class: 10C
Name: Jonas | Class: 9B
Name: Mia | Class: 11A

内容的提问来源于stack exchange，提问作者toni