计算包含数组中不同变量的目录中的文件数 - bash 脚本

Question

I have a bash script, which needs to check certain files for certain variables, and count how many files come back containing those variables.

As there is more than one variable I need to look for I decided to to use an array for the variables.

The code I am using is below:

#!/bin/bash

declare -a MYARRAY=('Variable One' 'Variable Two' 'Variable Three');
COUNT_MYARRAY=$(find $DIRECTORY -mtime -1 -exec grep -ln $MYARRAY {} \; | wc -l)

I have declared the $DIRECTORY in my real script. However, it does not seem to pick up files if they have the second and third variable within?

Can anyone see where I might be going wrong?

Answer 1

You can use grep s regex support and pass multiple expressions using 'var1\\|var2' . First construct the grep argument and then execute grep.

You don't need line numbers -n to grep to count the files...

grep can handle multiple files - it will be faster to pass multiple files to one grep with -exec ... + , rather then spawn grep for each file.

UPPER_CASE_VARIABLES are shouting at me and by convention upper vase variables are reserved for exported variables.

myarray=('Variable One' 'Variable Two' 'Variable Three')
arg=$(printf "%s\|" "${MYARRAY[@]}" | sed 's/\\|$//')
directory=.
count_myarray=$(find "$directory" -type f -mtime -1 -exec grep -l "$arg" {} + | wc -l)

Alternatively: you can pass multiple -exec arguments to find. So first from myarray construct arguments to find in the form -exec grep -l <the var> . Note that multiple variables can be in same files, so get unique filenames after grepping.

myarray=('Variable One' 'Variable Two' 'Variable Three');
findargs=()
for i in "${MYARRAY[@]}"; do
    findargs+=(-exec grep -l "$i" {} +)
done
directory=.
count_myarray=$(find "$directory" -type f -mtime -1 "${findargs[@]}" | sort -u | wc -l)

or similar:

count_myarray=$(printf '-exec\0grep\0-l\0%s\0{}\0+\0' "${myarray[@]}" | xargs -0 find "$directory" -type f -mtime -1 | sort -u | wc -l)

Remember to quote your variable expansions to protect against whitespaces or special characters in filenames and directory names.

Answer 2

Going wrong:
With echo $MYARRAY you find Variable One , not the string you want for grep.
Also note that it is better to use lowercase for your variable names. I will use ${directory} and not $DIRECTORY (and in double quotes for directories with a space).

You have more options with grep . When you want a file with 8 occurances counted one, you can not use the grep option -c . An useful option is -r . You are looking for something like

grep -Erl "Variable One|Variable Two|Variable Three" | wc -l

This is difficult when the variables might have special characters like $ or | .
Another option of grep is using the option -f FILE, Obtain patterns from FILE, one per line

So you should make a function that writes the variables to a file, and use something like

grep -rlFf "myVariablesFile" "${directory}" | wc -l

When the content of the file is changing rapidly, you might want to avoid the temporary file with

grep -rlFf <(function_that_writes_variables_to_stdout) "${directory}"| wc -l

or directly

grep -rlFf <(printf "%s\n" "${var1}" "${var2}" "${var3}") "${directory}" | wc -l