---

Manual Reference Pages  - get_command_argument (3fortran)

---

NAME

GET_COMMAND_ARGUMENT(3) - [SYSTEM:COMMAND LINE] Get command line arguments

SYNOPSIS

call get_command_argument(number [,value] [,length] & & [,status] [,errmsg])

       subroutine get_command_argument( number, value, length, &
       & status ,errmsg)

        integer(kind=**),intent(in)             :: number
        character(len=*),intent(out),optional   :: value
        integer(kind=**),intent(out),optional   :: length
        integer(kind=**),intent(out),optional   :: status
        character(len=*),intent(inout),optional :: errmsg

CHARACTERISTICS

o	a kind designated as ** may be any supported kind for the type meeting the conditions described herein.
o	NUMBER, LENGTH, and STATUS are scalar integer with a decimal exponent range of at least four.
o	VALUE and ERRMSG are scalar character variables of default kind.

DESCRIPTION

GET_COMMAND_ARGUMENT(3) retrieves or queries the n-th argument that was passed on the command line to the current program execution.

There is not anything specifically stated about what an argument is but in practice the arguments are strings split on whitespace unless the arguments are quoted. IFS values (Internal Field Separators) used by common shells are typically ignored and unquoted whitespace is almost always the separator.

Shells have often expanded command arguments and spell characters before passing them to the program, so the strings read are often not exactly what the user typed on the command line.

OPTIONS

o

NUMBER : is a non-negative number indicating which argument of the current program command line is to be retrieved or queried. : If NUMBER = 0, the argument pointed to is set to the name of the program (on systems that support this feature). : if the processor does not have such a concept as a command name the value of command argument 0 is processor dependent. : For values from 1 to the number of arguments passed to the program a value is returned in an order determined by the processor. Conventionally they are returned consecutively as they appear on the command line from left to right.

RESULT

o	VALUE : The VALUE argument holds the command line argument. If VALUE can not hold the argument, it is truncated to fit the length of VALUE. : If there are less than NUMBER arguments specified at the command line or if the argument specified does not exist for other reasons, VALUE will be filled with blanks.
o	LENGTH : The LENGTH argument contains the length of the n-th command line argument. The length of VALUE has no effect on this value, It is the length required to hold all the significant characters of the argument regardless of how much storage is provided by VALUE.
o	STATUS : If the argument retrieval fails, STATUS is a positive number; if VALUE contains a truncated command line argument, STATUS is -1; and otherwise the STATUS is zero.

EXAMPLES

Sample program:

    program demo_get_command_argument
    implicit none
    character(len=255)           :: progname
    integer                      :: count, i, argument_length, istat
    character(len=:),allocatable :: arg

     ! command name assuming it is less than 255 characters in length
      call get_command_argument (0, progname, status=istat)
      if (istat == 0) then
         print *, "The program’s name is " // trim (progname)
      else
         print *, "Could not get the program’s name " // trim (progname)
      endif

     ! get number of arguments
      count = command_argument_count()
      write(*,*)’The number of arguments is ’,count

      !
      ! allocate string array big enough to hold command line
      ! argument strings and related information
      !
      do i=1,count
         call get_command_argument(number=i,length=argument_length)
         if(allocated(arg))deallocate(arg)
         allocate(character(len=argument_length) :: arg)
         call get_command_argument(i, arg,status=istat)
         ! show the results
         write (*,’(i3.3,1x,i0.5,1x,i0.5,1x,"[",a,"]")’) &
         & i,istat,argument_length,arg
      enddo

    end program demo_get_command_argument

Results:

    ./demo_get_command_argument a  test ’of getting  arguments ’ " leading"

     > The program’s name is ./demo_get_command_argument
     > The number of arguments is            4
     >001 00000 00001 [a]
     >002 00000 00004 [test]
     >003 00000 00022 [of getting  arguments ]
     >004 00000 00008 [ leading]

STANDARD

Fortran 2003

SEE ALSO

GET_COMMAND(3), COMMAND_ARGUMENT_COUNT(3)

Fortran intrinsic descriptions (license: MIT) @urbanjost

---

Nemo Release 3.1

get_command_argument (3fortran)

November 02, 2024

Generated by manServer 1.08 from 391f1fc2-41cb-4a72-9ba2-cff3b6480fbf using man macros.