FortranArgsParser

FortranArgsParser is very simple module for parsing command line arguments.

FortranArgsParser functions:

1. Parse integer arguments in format --any_name VALUE with support of default value
2. Parse real arguments in format --any_name VALUE with support of default value
3. Parse logical arguments in format -X or --any_name
4. Displaying help if -h is specified
5. Displaying help and exiting if required argument is missing

Notes

1. Argument name format is user specified, does not have to start with -- or -, however it should
2. Displaying help is also defined by user (see. test.f90)

More motes

This project was created and developed as a part of other project and was developed for specific and limited functionality. It might require some work to be useful in other projects.

Usage

See test.f90 for full example.

Module provides 4 functions:

1. CheckForHelp() - checks if user used -h flag and returns .TRUE.
2. ParseArgumentInt(ArgName, UseDefault, Default, StatusCorrect, StatusIncorrect, PrintHelp, Help) - returns integer value of argument
3. ParseArgumentReal(ArgName, UseDefault, Default, StatusCorrect, StatusIncorrect, PrintHelp, Help) - returns real value of argument
4. ParseArgumentLogical(ArgName, UseDefault, Default, StatusCorrect, StatusIncorrect, PrintHelp, Help) - returns logical value of flag
5. ParseArgumentString(ArgName, UseDefault, Default, StatusCorrect, StatusIncorrect, PrintHelp, Help) - returns CHARACTER(len=128) value of flag

Function arguments:

• ArgName: strign with argument / flag name (ex. --szie, -L, --ANY-NAME...)
• UseDefault: logical flag if this argument has default value (.TRUE. or .FALSE.)
• Default: integer, real or logical (depending on function used) default value
• StatusCorrect: integer container for number of correctly processed arguments. Must be initiated with 0
• StatusIncorrect: integer container for number of incorrectly processed arguments. Must be initiated with 0
• PrintHelp: logical flag if help should be printed: if help is printed arguments are not processed - see test.f90 for idea of this approach
• Help: string with help

Error handling

Ability to print full help if any of required arguments fail requires double pass of all Parse... functions. In provided example this is achieved by using a loop.

Example

For given code (part of test.f90 example):

sizex = ParseArgumentInt("--sizex", .FALSE., 0, ...)
sizey = ParseArgumentInt("--sizey", .TRUE., 64, ...)

StartTime = ParseArgumentReal("--starttime", .TRUE., 0.0, ...)
StopTime = ParseArgumentReal("--stoptime", .FALSE., 0.0, ...)

UseStuff = ParseArgumentLogical("-S", .TRUE., .FALSE., ...)
UseMoreStuff = ParseArgumentLogical("-M", .TRUE., .FALSE., ...)

FileName = ParseArgumentString("--filename", .FALSE., "", ...)

write(*,"(A15,I8)") "sizex = ", sizex
write(*,"(A15,I8)") "sizey = ", sizey

write(*,"(A15,F8.4)") "starttime = ", StartTime
write(*,"(A15,F8.4)") "stoptime = ", StopTime

write(*,"(A15,L8)") "use stuff = ", UseStuff
write(*,"(A15,L8)") "use more stuff = ", UseMoreStuff

write(*,"(A18,A8)") "FileName = ", FileName

Results might be like that:

$ ./test.exe --sizex 256 --stoptime 15.677 -M --filename test
          sizex =      256
          sizey =       64
      starttime =   0.0000
       stoptime =  15.6770
      use stuff =        F
 use more stuff =        T
       FileName = test   

$ ./test.exe --sizex 256 --sizey 32 -S --stoptime 15.677 -M --filename "A B C D"
          sizex =      256
          sizey =       32
      starttime =   0.0000
       stoptime =  15.6770
      use stuff =        T
 use more stuff =        T
       FileName = A B C D 

$ ./test.exe --starttime -32.5 --sizex 256 --sizey 32 -S --stoptime 15.677 --filename "A B C D"
          sizex =      256
          sizey =       32
      starttime = -32.5000
       stoptime =  15.6770
      use stuff =        T
 use more stuff =        F
       FileName = A B C D