xref: /petsc/src/sys/fileio/mpiuopen.c (revision 48a46eb9bd028bec07ec0f396b1a3abb43f14558)

#define PETSC_DESIRE_FEATURE_TEST_MACROS /* for popen() */
/*
      Some PETSc utility routines to add simple parallel IO capabilities
*/
#include <petscsys.h>
#include <petsc/private/logimpl.h>
#include <errno.h>

/*@C
    PetscFOpen - Has the first process in the communicator open a file;
    all others do nothing.

    Logically Collective

    Input Parameters:
+   comm - the communicator
.   name - the filename
-   mode - the mode for fopen(), usually "w"

    Output Parameter:
.   fp - the file pointer

    Level: developer

    Notes:
       NULL (0), "stderr" or "stdout" may be passed in as the filename

    Fortran Note:
    This routine is not supported in Fortran.

.seealso: `PetscFClose()`, `PetscSynchronizedFGets()`, `PetscSynchronizedPrintf()`, `PetscSynchronizedFlush()`,
          `PetscFPrintf()`
@*/
PetscErrorCode PetscFOpen(MPI_Comm comm, const char name[], const char mode[], FILE **fp) {
  PetscMPIInt rank;
  FILE       *fd;
  char        fname[PETSC_MAX_PATH_LEN], tname[PETSC_MAX_PATH_LEN];

  PetscFunctionBegin;
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  if (rank == 0) {
    PetscBool isstdout, isstderr;
    PetscCall(PetscStrcmp(name, "stdout", &isstdout));
    PetscCall(PetscStrcmp(name, "stderr", &isstderr));
    if (isstdout || !name) fd = PETSC_STDOUT;
    else if (isstderr) fd = PETSC_STDERR;
    else {
      PetscBool devnull;
      PetscCall(PetscStrreplace(PETSC_COMM_SELF, name, tname, PETSC_MAX_PATH_LEN));
      PetscCall(PetscFixFilename(tname, fname));
      PetscCall(PetscStrbeginswith(fname, "/dev/null", &devnull));
      if (devnull) PetscCall(PetscStrcpy(fname, "/dev/null"));
      PetscCall(PetscInfo(0, "Opening file %s\n", fname));
      fd = fopen(fname, mode);
      PetscCheck(fd, PETSC_COMM_SELF, PETSC_ERR_FILE_OPEN, "Unable to open file %s", fname);
    }
  } else fd = NULL;
  *fp = fd;
  PetscFunctionReturn(0);
}

/*@C
    PetscFClose - Has the first processor in the communicator close a
    file; all others do nothing.

    Logically Collective

    Input Parameters:
+   comm - the communicator
-   fd - the file, opened with PetscFOpen()

   Level: developer

    Fortran Note:
    This routine is not supported in Fortran.

.seealso: `PetscFOpen()`
@*/
PetscErrorCode PetscFClose(MPI_Comm comm, FILE *fd) {
  PetscMPIInt rank;
  int         err;

  PetscFunctionBegin;
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  if (rank == 0 && fd != PETSC_STDOUT && fd != PETSC_STDERR) {
    err = fclose(fd);
    PetscCheck(!err, PETSC_COMM_SELF, PETSC_ERR_SYS, "fclose() failed on file");
  }
  PetscFunctionReturn(0);
}

#if defined(PETSC_HAVE_POPEN)
static char PetscPOpenMachine[128] = "";

/*@C
      PetscPClose - Closes (ends) a program on processor zero run with PetscPOpen()

     Collective, but only process 0 runs the command

   Input Parameters:
+   comm - MPI communicator, only processor zero runs the program
-   fp - the file pointer where program input or output may be read or NULL if don't care

   Level: intermediate

   Notes:
       Does not work under Windows

.seealso: `PetscFOpen()`, `PetscFClose()`, `PetscPOpen()`

@*/
PetscErrorCode PetscPClose(MPI_Comm comm, FILE *fd) {
  PetscMPIInt rank;

  PetscFunctionBegin;
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  if (rank == 0) {
    char buf[1024];
    while (fgets(buf, 1024, fd))
      ; /* wait till it prints everything */
    (void)pclose(fd);
  }
  PetscFunctionReturn(0);
}

/*@C
      PetscPOpen - Runs a program on processor zero and sends either its input or output to
          a file.

     Logically Collective, but only process 0 runs the command

   Input Parameters:
+   comm - MPI communicator, only processor zero runs the program
.   machine - machine to run command on or NULL, or string with 0 in first location
.   program - name of program to run
-   mode - either r or w

   Output Parameter:
.   fp - the file pointer where program input or output may be read or NULL if don't care

   Level: intermediate

   Notes:
       Use PetscPClose() to close the file pointer when you are finished with it
       Does not work under Windows

       If machine is not provided will use the value set with PetsPOpenSetMachine() if that was provided, otherwise
       will use the machine running node zero of the communicator

       The program string may contain ${DISPLAY}, ${HOMEDIRECTORY} or ${WORKINGDIRECTORY}; these
    will be replaced with relevant values.

.seealso: `PetscFOpen()`, `PetscFClose()`, `PetscPClose()`, `PetscPOpenSetMachine()`

@*/
PetscErrorCode PetscPOpen(MPI_Comm comm, const char machine[], const char program[], const char mode[], FILE **fp) {
  PetscMPIInt rank;
  size_t      i, len, cnt;
  char        commandt[PETSC_MAX_PATH_LEN], command[PETSC_MAX_PATH_LEN];
  FILE       *fd;

  PetscFunctionBegin;
  /* all processors have to do the string manipulation because PetscStrreplace() is a collective operation */
  if (PetscPOpenMachine[0] || (machine && machine[0])) {
    PetscCall(PetscStrcpy(command, "ssh "));
    if (PetscPOpenMachine[0]) {
      PetscCall(PetscStrcat(command, PetscPOpenMachine));
    } else {
      PetscCall(PetscStrcat(command, machine));
    }
    PetscCall(PetscStrcat(command, " \" export DISPLAY=${DISPLAY}; "));
    /*
        Copy program into command but protect the " with a \ in front of it
    */
    PetscCall(PetscStrlen(command, &cnt));
    PetscCall(PetscStrlen(program, &len));
    for (i = 0; i < len; i++) {
      if (program[i] == '\"') command[cnt++] = '\\';
      command[cnt++] = program[i];
    }
    command[cnt] = 0;

    PetscCall(PetscStrcat(command, "\""));
  } else {
    PetscCall(PetscStrcpy(command, program));
  }

  PetscCall(PetscStrreplace(comm, command, commandt, 1024));

  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  if (rank == 0) {
    PetscCall(PetscInfo(NULL, "Running command :%s\n", commandt));
    PetscCheck((fd = popen(commandt, mode)), PETSC_COMM_SELF, PETSC_ERR_LIB, "Cannot run command %s", commandt);
    if (fp) *fp = fd;
  }
  PetscFunctionReturn(0);
}

/*@C
      PetscPOpenSetMachine - Sets the name of the default machine to run PetscPOpen() calls on

     Logically Collective, but only process 0 runs the command

   Input Parameter:
.   machine - machine to run command on or NULL for the current machine

   Options Database:
.   -popen_machine <machine> - run the process on this machine

   Level: intermediate

.seealso: `PetscFOpen()`, `PetscFClose()`, `PetscPClose()`, `PetscPOpen()`
@*/
PetscErrorCode PetscPOpenSetMachine(const char machine[]) {
  PetscFunctionBegin;
  if (machine) {
    PetscCall(PetscStrcpy(PetscPOpenMachine, machine));
  } else {
    PetscPOpenMachine[0] = 0;
  }
  PetscFunctionReturn(0);
}

#endif