Contents

Temporary File Management (scratch)

Module: utils_scratch

Overview

Provides utilities for managing temporary scratch files in SPEX, primarily for logging and system operations. The scratch module creates temporary log files that are automatically cleaned up when SPEX exits.

Key Features

  • Automatic temporary log file management

  • Session-based scratch file tracking

  • Automatic cleanup on SPEX exit

  • Integration with SPEX logging system

  • Error handling and reporting

API Reference

Subroutines

init

scr%init(ier)

Initialize scratch file system

Parameters:

ier – Error status (integer, output)

Returns:

None

Sets up temporary scratch files for logging and system operations.

Status Codes: - ier = 0: Success - ier ≠ 0: Failure (cannot create scratch files)

addlog

scr%addlog(string)

Add message to scratch log file

Parameters:

string – Message to add (character(*))

Returns:

None

Writes a string to the scratch log file.

addsys

scr%addsys(string)

Add message to scratch system file

Parameters:

string – Message to add (character(*))

Returns:

None

Writes a string to the scratch system file.

final

scr%final()

Clean up scratch files

Returns:

None

Closes and deletes all scratch files. This should only happen at successful exit of SPEX.

Usage Examples

Basic Scratch File Initialization

use utils_scratch
integer :: ier

! Initialize scratch file system
call scr%init(ier)
if (ier == 0) then
   write(*,*) 'Scratch files initialized successfully'
else
   write(*,*) 'Error: Cannot create scratch files'
endif

Adding Messages to Scratch Files

use utils_scratch
integer :: ier

! Initialize scratch system
call scr%init(ier)
if (ier == 0) then
   ! Add messages to log and system files
   call scr%addlog('Starting data processing...')
   call scr%addsys('System initialized')

   ! ... perform operations ...

   call scr%addlog('Data processing completed')
   call scr%addsys('System shutting down')

   ! Clean up scratch files
   call scr%final()
endif

Error Handling with Scratch Files

use utils_scratch
use utils_message
integer :: ier
type(message) :: mesg

! Initialize with error handling
call scr%init(ier)
if (ier /= 0) then
   call mesg%sper('Failed to initialize scratch files')
   call mesg%sper('Check directory write permissions')
else
   ! Add log messages
   call scr%addlog('Application started')

   ! ... perform operations ...

   ! Add system messages
   call scr%addsys('Operation completed successfully')

   ! Clean up
   call scr%final()
endif

Integration with SPEX Workflow

use utils_scratch
use utils_message
integer :: ier
type(message) :: mesg

! Initialize scratch files at start of SPEX session
call scr%init(ier)
if (ier == 0) then
   call scr%addlog('SPEX session started')
   call scr%addsys('System ready')

   ! ... SPEX operations ...

   ! Log important events
   call scr%addlog('Data loaded successfully')
   call scr%addsys('Memory allocated')

   ! ... more operations ...

   ! Final cleanup when SPEX exits
   call scr%final()
else
   call mesg%sper('SPEX cannot start: scratch file initialization failed')
endif

Notes

Scratch File Management

  • Scratch files are automatically created with unique names based on process ID

  • Files are stored in the current working directory with names like spexsysXXXXXXXXXX.dum and spexlogXXXXXXXXXX.dum

  • All scratch files are automatically deleted on scr%final()

  • Scratch files are used primarily for logging and system operations

Error Handling

  • Check ier after initialization

  • ier = 0 indicates success

  • Non-zero values indicate errors (usually permission issues)

  • Use mesg%sper() for error reporting

Performance Considerations

  • Scratch files use disk I/O for logging

  • Minimal performance impact for normal operations

  • Files are small and temporary

  • Automatic cleanup prevents disk space issues

Best Practices

  1. Always initialize scratch system at SPEX startup

  2. Always clean up with scr%final() at SPEX exit

  3. Use for logging important events and system messages

  4. Check initialization errors and handle gracefully

  5. Use with message system for consistent error reporting

Common Use Cases

Use Case

Description

Example

SPEX Session Logging

Track SPEX operations and events

Startup, data loading, processing steps

System Monitoring

Record system state and operations

Memory allocation, file operations

Error Diagnosis

Capture debug information

Problem analysis and troubleshooting

Session Tracking

Monitor SPEX workflow progression

Step-by-step operation logging

See Also