如何将Bash脚本生成的字符串传递给其他命令作为参数？

First, let's get the core task done: capturing your script's output and passing it correctly to the grun command. Here are two straightforward ways:

Option 1: Store the String in a Variable (Reusable) #

Use command substitution to capture the output of your script into a variable, then pass it to grun with proper quoting to preserve spaces and punctuation:

# Generate the target string and store it
target_string=$(
    arr_size=(small medium large)
    arr_pkg=(vim)
    # Replace echo -n with printf for cross-shell reliability
    printf "pkg %s" "${arr_pkg[0]}"
    for size in "${arr_size[@]}"; do
        printf ", size %s" "$size"
    done
)

# Use the variable in your grun command (note the double quotes)
grun --file 123.txt --tt="$target_string"

The double quotes around "$target_string" are crucial—they ensure the entire string is passed as a single argument to --tt without splitting on spaces or commas.

Option 2: Inline the Generation (No Variable Needed) #

If you don't need to reuse the string elsewhere, you can embed the generation directly into the grun command:

grun --file 123.txt --tt="$(
    arr_size=(small medium large)
    arr_pkg=(vim)
    printf "pkg %s" "${arr_pkg[0]}"
    for size in "${arr_size[@]}"; do
        printf ", size %s" "$size"
    done
)"

Your current script works, but we can make it cleaner, more portable, and easier to maintain:

1. Ditch echo -n for printf #

echo -n has inconsistent behavior across different shell versions (some don't support the -n flag). printf is standardized and reliable for formatted, newline-free output—this is why we used it in the examples above.

2. Simplify the Package Loop (For Single Package) #

Since your arr_pkg only has one element (vim), you can skip the loop entirely and directly reference the first element:

printf "pkg %s" "${arr_pkg[0]}"

If you ever add more packages later, you can adjust this to loop through them and append ", pkg $pkg" for each additional one.

3. Build the String Incrementally (Readable) #

Instead of printing piecemeal, build the string step by step in a variable—this makes debugging and modifications easier:

arr_size=(small medium large)
arr_pkg=(vim)

# Start with the package portion
result="pkg ${arr_pkg[0]}"

# Append each size
for size in "${arr_size[@]}"; do
    result="$result, size $size"
done

# Pass to grun
grun --file 123.txt --tt="$result"

4. Array Joining (Bash 4+) #

If you're using Bash 4 or newer, you can join the size array without a loop for a more concise approach:

arr_size=(small medium large)
arr_pkg=(vim)

# Join size elements with ", size "
IFS=", size "
size_part="${arr_size[*]}"
unset IFS

# Build full string
full_string="pkg ${arr_pkg[0]}, size $size_part"

grun --file 123.txt --tt="$full_string"

This works because setting IFS (Internal Field Separator) to ", size " tells Bash to join the array elements with that string when using ${arr_size[*]}.

Final Tip #

Always test with edge cases (like empty arrays, multiple packages) if you plan to expand this script later. And remember: double quotes around variables are your friend when you need to preserve whitespace and special characters.

内容的提问来源于stack exchange，提问作者mebb