FILE_MERGE
Merge Two Sorted Files

FILE_MERGE is a FORTRAN90 program which merges two sorted files.

Note that on Unix systems, the command merge is faster, more flexible and efficient.

Usage:

file_merge input1 input2 output

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

FILE_MERGE is available in a FORTRAN90 version

Related Data and Programs:

CHRPAK, a FORTRAN90 library which can work with characters and strings.

FILE_ROW_REVERSE, a FORTRAN90 program which makes a copy of a file with the lines ("rows") in reverse order.

FILE_TRANSPOSE, a FORTRAN90 program which makes a "transposed" copy of a file, in which the I-th "word" of the J-th line becomes the J-th word of the I-th line.

FILUM, a FORTRAN90 library which can work with information in text files.

Source Code:

• file_merge.f90 the source code.
• file_merge.sh, commands to compile the source code;

Examples and Tests:

• file1.txt, a file of 26 lines, sorted alphabetically.
• file2.txt, a file of 19 lines, sorted alphabetically, with 5 words that duplicate words in the first file.
• file3.txt, a file of 40 lines, sorted alphabetically, created by the command

  file_merge file1.txt file2.txt file3.txt

List of Routines:

• MAIN is the main program for FILE_MERGE.
• CH_LOW lowercases a single character.
• GET_UNIT returns a free FORTRAN unit number.
• MERGE_SORTED_FILES merges two sorted files into a third.
• S_LOW replaces all uppercase letters by lowercase ones.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the FORTRAN90 source codes.