How to Check Whether a File Is Empty or Not

How to check if a file is empty in Bash?

Misspellings are irritating, aren't they? Check your spelling of empty, but then also try this:

#!/bin/bash -e

if [ -s diff.txt ]; then
        # The file is not-empty.
        rm -f empty.txt
        touch full.txt
else
        # The file is empty.
        rm -f full.txt
        touch empty.txt
fi

I like shell scripting a lot, but one disadvantage of it is that the shell cannot help you when you misspell, whereas a compiler like your C++ compiler can help you.

Notice incidentally that I have swapped the roles of empty.txt and full.txt, as @Matthias suggests.

How to check whether a file is empty or not

>>> import os
>>> os.stat("file").st_size == 0
True

How can I check if a file is empty or not? and empty it before writing if not?

If you want clear out any existing data in the file first and write your output whether the file was empty or not, that's easy: just use

open('out.txt', 'w')

'w' means "write", 'a' means "append".

If you want to check whether the file has data in it and not write anything at all if there is data, then Hypnos' answer would be appropriate. Check the file size and skip the file-writing code if the file is not empty.

Most efficient way to check if a file is empty in Java on Windows

Check if the first line of file is empty:

BufferedReader br = new BufferedReader(new FileReader("path_to_some_file"));     
if (br.readLine() == null) {
    System.out.println("No errors, and file empty");
}

check if file is empty or not in c

it does'nt work because you have to fopen it and fseek to the end first:

FILE *fptr;
if ( !( fptr = fopen( "saving.txt", "r" ))){
    printf( "File could not be opened to retrieve your data from it.\n" );
}
else {
    fseek(fptr, 0, SEEK_END);
    unsigned long len = (unsigned long)ftell(fptr);
    if (len > 0) {  //check if the file is empty or not.
        rewind(fptr);
        while ( !feof( fptr ) ){
            fscanf( fptr, "%f\n", &p.burst_time );
            AddProcess(&l,p.burst_time);
        }
    }
    fclose( fptr );
}

How can I check if a file is empty?

You can use file.size:

empty = filenames[file.size(filenames) == 0L]

file.size is a shortcut for file.info:

info = file.info(filenames)
empty = rownames(info[info$size == 0L, ])

Incidentally, there’s a better way of listing text files than using grep: specify the pattern argument to list.files:

list.files(pattern = '\\.txt$')

Note that the pattern needs to be a regular expression, not a glob — and the same is true for grep!

Check file empty or not

You may use this awk for this:

awk 'NF {exit 1}' file && echo "empty" || echo "not empty"

Condition NF will be true only if there is non-whitespace character in the file.

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