How to copy files that having line number > 100 to other folder - shell

Question

I want to copy files that having 100 lines or more to another folder:
$ cd "/home/john/folder a"
$ wc -l *
10 file1.txt
50 file2.txt
100 file3.txt
150 file4.txt
I want to copy file file3.txt and file4.txt (files that having 100 lines or more) to folder /home/john/folder b.
Can someone help me please? Thank you very much.

Answer 1

Try this:
declare -i numfile
for f in *; do
numfile=$([ -f "$f" ] && cat "$f" | wc -l )
[ $numfile -ge 100 ] && cp "$f" otherdir
done
For each files in current directory, numfile is assigned the number of lines of the file.
If numfile is greater or equal to 100, file is copied to otherdir.
Edit :
As William Pursell mentionned, a more robust approach would be to test if the item is a file before executing comparison and copy commands:
for f in *; do
if [ -f "$f" ]; then
[ "$(wc -l < $f)" -ge 100 ] && cp "$f" otherdir;
fi
done

Answer 2

Here is one more:
# Assuming that we are in source folder ...
cp $(wc -l *|grep -Eo '[0-9]{3,} (.*)'|head -n -1|cut -d ' ' -f 2) /dev/null "/home/john/folder b"
The head removes the total line printed by wc, and the /dev/null takes care of the case that you don't have any files matching the criterium.
Of course this solution - as the other ones presented here - will get you into problems, if your source directory contains that many files, that the maximum command line length will be exceeded.

Answer 3

Try something like this (POSIX sh):
#!/bin/sh
SOURCE_FOLDER="/home/john/folder a"
COPY_TO="/home/john/folder b"
for dir in "$SOURCE_FOLDER" "$COPY_TO"; do
if [ ! -d "$dir" ]; then
echo "Directory ${dir} does not exist." >&2
exit 1
fi
done
if [ "x`ls -A "$SOURCE_FOLDER"`" = "x" ]; then
echo "Directory '${SOURCE_FOLDER}' is empty." >&2
exit 1
fi
for file in "$SOURCE_FOLDER"/*; do
LINES=`wc -l < "$file"`
echo "File ${file} has ${LINES} lines..."
if [ "$LINES" -ge 100 ]; then
echo "Copying ${file}..."
cp -a "$file" "${COPY_TO}/"
fi
done
Here's a Bash version for systems with Bash (you said Unix, not Linux, so you probably want the top version):
#!/bin/bash
SOURCE_FOLDER="/home/john/folder a"
COPY_TO="/home/john/folder b"
for dir in "$SOURCE_FOLDER" "$COPY_TO"; do
if [[ ! -d "$dir" ]]; then
echo "Directory ${dir} does not exist." >&2
exit 1
fi
done
if [[ -z "$(ls -A "$SOURCE_FOLDER")" ]]; then
echo "Directory '${SOURCE_FOLDER}' is empty." >&2
exit 1
fi
for file in "$SOURCE_FOLDER"/*; do
LINES="$(wc -l < "$file"')"
echo "File ${file} has ${LINES} lines..."
if [[ "$LINES" -ge 100 ]]; then
echo "Copying ${file}..."
cp -a "$file" "${COPY_TO}/"
fi
done
I tested it like this:
$ mkdir "folder a"
$ mkdir "folder b"
$ chmod +x script.sh
$ cd folder\ a/
$ seq 1 1000 > file1.txt
$ seq 1 1000 > file2.txt
$ seq 1 100 > file4.txt
$ seq 1 100 > file3.txt
$ seq 1 99 > file4.txt
$ seq 1 1 > file5.txt
$ seq 1 20 > file6.txt
$ cd ..
$ ./script.sh
File /.../dev/scratch/stack/folder a/file1.txt has 1000 lines...
Copying /.../dev/scratch/stack/folder a/file1.txt...
File /.../dev/scratch/stack/folder a/file2.txt has 1000 lines...
Copying /.../dev/scratch/stack/folder a/file2.txt...
File /.../dev/scratch/stack/folder a/file3.txt has 100 lines...
Copying /.../dev/scratch/stack/folder a/file3.txt...
File /.../dev/scratch/stack/folder a/file4.txt has 99 lines...
File /.../dev/scratch/stack/folder a/file5.txt has 1 lines...
File /.../dev/scratch/stack/folder a/file6.txt has 20 lines...
I encourage you to step through this line by line, figuring out how each part of the script works, to help you with similar tasks in the future.
I'll explain a few things here:
wc -l < "$file" gives us only the line count of the file, without the filename.
[ "$LINES" -ge 100 ] is true if there are at least 100 lines in the file.
echo "..." >&2 outputs a line to standard error rather than standard output.
cp -a copys a file while retaining all of it's attributes, such as owner, permissions, and modification time.
Make sure to quote all variables unless you have a good reason not to, to prevent issues with whitespace.