114 lines
5.6 KiB
Plaintext
114 lines
5.6 KiB
Plaintext
c FOREXEC.INC - interface file for C library routines
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c This include file along with the CEXEC.LIB library has been included
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c with your FORTRAN 3.30 to show you how easy it is to call routines
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c written in our new C 3.00 release. The CEXEC.LIB contains several
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c routines from the C library which we think you will find useful in
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c extending the power of your FORTRAN programs.
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c
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c The new Microsoft FORTRAN 3.30, PASCAL 3.30, and C 3.00 releases
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c have been designed so that libraries or subprograms can be written
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c in any one of these languages and used in any other.
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c
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c Try compiling and running the demonstration program DEMOEXEC.FOR
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c to see some actual examples.
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c C function
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c
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c int system(string)
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c char *string;
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c
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c The system() function passes the given C string (00hex terminated)
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c to the DOS command interpreter (COMMAND.COM), which interprets and
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c executes the string as an MS-DOS command. This allows MS-DOS commands
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c (i.e., DIR or DEL), batch files, and programs to be executed.
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c
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c Example usage in FORTRAN
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c
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c integer*2 system (the return type must be declared)
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c ...
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c i = system('dir *.for'c) (notice the C literal string '...'c)
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c
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c The interface to system is given below. The [c] attribute is given
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c after the function name. The argument string has the attribute
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c [reference] to indicate that the argument is passed by reference.
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c Normally, arguments are passed to C procedures by value.
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interface to integer*2 function system [c]
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+ (string[reference])
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character*1 string
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end
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c C function
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c
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c int spawnlp(mode,path,arg0,arg1,...,argn)
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c int mode; /* spawn mode */
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c char *path; /* pathname of program to execute */
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c char *arg0; /* should be the same as path */
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c char *arg1,...,*argn; /* command line arguments */
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c /* argn must be NULL */
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c
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c The spawnlp (to be referenced in FORTRAN as spawn) creates and
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c executes a new child process. There must be enough memory to load
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c and execute the child process. The mode argument determines which
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c form of spawn is executed as follows:
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c
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c Value Action
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c
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c 0 Suspend parent program and execute the child program.
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c When the child program terminates, the parent program
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c resumes execution. The return value from spawn is -1
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c if an error has occured or if the child process has
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c run, the return value is the child processes return
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c code.
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c
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c 2 Overlay parent program with the child program. The
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c child program is now the running process and the
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c parent process is terminated. spawn only returns
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c a value if there has been a recoverable error. Some
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c errors can not be recovered from and execution will
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c terminate by safely returning to DOS. This might
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c happen if there is not enough memory to run the new
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c process.
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c
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c The path argument specifies the file to be executed as the child
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c process. The path can specify a full path name (from the root
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c directory \), a partial path name (from the current working directory),
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c or just a file name. If the path argument does not have a filename
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c extension or end with a period (.), the spawn call first appends
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c the extension ".COM" and searches for the file; if unsuccessful, the
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c extension ".EXE" is tried. The spawn routine will also search for
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c the file in any of the directories specified in the PATH environment
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c variable (using the same procedure as above).
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c
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c Example usage in FORTRAN
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c
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c integer*2 spawn (the return type must be declared)
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c ...
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c i = spawn(0, loc('exemod'c), loc('exemod'c),
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c + loc('demoexec.exe'c), int4(0)) (execute as a child)
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c
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c The interface to spawnlp is given below. The [c] attribute is given
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c after the function name. The [varying] attribute indicates that a
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c variable number of arguments may be given to the function. The
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c [alias] attribute has to be used because the C name for the function
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c spawnlp has 7 characters. Names in FORTRAN are only significant to
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c 6 characters, so we 'alias' the FORTRAN name spawn to the actual C
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c name spawnlp. Notice in the example above the C strings are passed
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c differently from the system function. This is because the string
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c arguments to spawn are undeclared in the interface below and assumed
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c to be passed by value. The C spawnlp function is expecting the
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c addresses of the strings (not the actual characters), so we use the
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c LOC() function to pass the address (remember that functions with the
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c [c] attribute pass arguments by value). The last parameter to the
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c spawn routine must be a C NULL pointer which is a 32-bit integer 0,
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c so we use the INT4(0) function to pass this number by value as the
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c last parameter.
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interface to integer*2 function spawn
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+ [c,varying,alias:'spawnlp']
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+ (mode)
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integer*2 mode
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end
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