Editing Merge multiple text files into one file


== Steps ==
Step 1: check the last line of text file is [[Return symbol | newline]] (return symbol)<ref>[https://stackoverflow.com/questions/34943632/linux-check-if-there-is-a-newline-at-the-end-of-a-file eof - Linux - check if there is a newline at the end of a file - Stack Overflow]</ref>
* {{kbd | key=<nowiki>tail -c 1 file.txt</nowiki>}} on {{Linux}}. Parameter "-c <span style="text-decoration: underline;">number</span>: The location is <span style="text-decoration: underline;">number</span> bytes." quoted from the [http://man7.org/linux/man-pages/man1/tail.1.html commands manual]. If the last line is newline, returned result will be empty. {{exclaim}} How to check multiple files?
* (optional) If the last line is not newline, you may add the new line manually. See details on [https://unix.stackexchange.com/questions/31947/how-to-add-a-newline-to-the-end-of-a-file bash - How to add a newline to the end of a file? - Unix & Linux Stack Exchange]

Step 2: Merge the content
* {{kbd | key=<nowiki>copy *.txt > bundle.txt </nowiki>}} or {{kbd | key=<nowiki>copy file1.txt file2.txt > bundle.txt </nowiki>}} on {{Win}}
* {{kbd | key=<nowiki>cat *.txt > bundle.txt </nowiki>}} or {{kbd | key=<nowiki>cat file1.txt file2.txt > bundle.txt </nowiki>}} on {{Linux}} & {{Mac}}<ref>[http://www.maclife.com/article/columns/terminal_101_join_multiple_files_together_cat Terminal 101: Join Multiple Files Together with Cat]</ref><ref>[https://unix.stackexchange.com/questions/3770/how-to-merge-all-text-files-in-a-directory-into-one How to merge all (text) files in a directory into one? - Unix & Linux Stack Exchange]</ref>

Step 3: (optional) Remove the duplicated lines
* {{kbd | key=sort -us -o bundle_unique.txt bundle.txt}}<ref>[http://unix.stackexchange.com/questions/19641/how-to-remove-duplicate-lines-in-a-large-multi-gb-textfile linux - How to remove duplicate lines in a large multi-GB textfile? - Unix & Linux Stack Exchange]</ref> OS: {{Linux}}, cygwin of {{Win}} "-u means Unique keys; -s means stable sort; -o means output" quoted from [https://www.computerhope.com/unix/usort.htm sort] manual.

Step 4: (optional) Remove the heading of CSV file

Step 5: Verify the merged file
* count number of lines {{kbd | key=<nowiki>wc -l merged.filename</nowiki>}}<ref>[https://www.tecmint.com/wc-command-examples/ 6 WC Command Examples to Count Number of Lines, Words, Characters in Linux]</ref>

== References ==
<references />

[[Category:Data Science]]
[[Category:String manipulation]]