Creating an arbitrarily large “fake” file

You can use awk for the job:

$ curl -O https://raw.githubusercontent.com/qtproject/qt-mobility\
/d7f10927176b8c3603efaaceb721b00af5e8605b/demos/qmlcontacts/contents/\
example.vcf

$ gawk ' /BEGIN:VCARD/ { close(fn); ++a; fn=sprintf("card_%02d.vcf", a); 
        print "Writing: ", fn } { print $0 > fn; } ' example.vcf
Writing:  card_01.vcf
Writing:  card_02.vcf
Writing:  card_03.vcf
Writing:  card_04.vcf
Writing:  card_05.vcf
Writing:  card_06.vcf
Writing:  card_07.vcf
Writing:  card_08.vcf
Writing:  card_09.vcf

$ cat card_0* > all.vcf
$ cmp example.vcf all.vcf
$ echo $?
0

Details

The awk line works like this: a is counter that is incremented on each BEGIN:VCARD line and at the same time the output filename is constructed using sprintf (stored in fn). For each line the current line ($0) is appended to the current file (named fn).

The last echo $? means that the cmp was successful, i.e. all single files concatenated are equal to the original example vcf example.

Note that the output redirection in awk works differently than in shell. That means that with > fn awk first checks if the file is already open. If it is already open then awk appends to it. If it is not then it opens and truncates it.

Because of this redirection logic we have to explicitly close the implicitly opened files, since otherwise the call would hit the open file limit in cases where the input file contains many records.

I created a script that will do this. The script converts all hard-links it finds in a source directory (first argument) that are the same as in the working directory (optional second argument) into symbolic links:

https://gist.github.com/rubo77/7a9a83695a28412abbcd

It has an option -n for a dry-run, that doesn't do anything but shows what would be done.

Main part:

$WORKING_DIR=./
#relative source directory from working directory:
$SOURCE_DIR=../otherdir/with/hard-links/with-the-same-inodes

# find all files in WORKING_DIR
cd "$WORKING_DIR"
find "." -type f -links +1 -printf "%i %p\n" | \
  while read working_inode working_on
do
    find "$SOURCE_DIR" -type f -links +1 -printf "%i %p\n" | sort -nk1 | \
      while read inode file
    do
        if [[ $inode == $working_inode ]]; then
            ln -vsf "$file" "$working_on"
        fi
    done
done

The -links +1 --> Will find all files that have MORE than 1 link. Hardlinked files have a link count of at least two.