Redirect Command Output to File in MS-DOS 6.22

Redirecting command output to a text file in MS-DOS 6.22 allows you to save terminal results for logging, troubleshooting, or later review. This article explains the syntax for standard redirection, detailing how to create new files, overwrite existing ones, and append data to existing files using the command-line interface.

The Overwrite Operator (>)

To send the output of a command to a text file, use the single greater-than symbol (>). If the designated file does not exist, MS-DOS creates it. If the file already exists, MS-DOS overwrites its contents without warning.

Syntax:

COMMAND > FILENAME.EXT

Example: To redirect the directory listing of the current folder to a file named DIRLIST.TXT:

DIR > DIRLIST.TXT

The Append Operator (>>)

To add the output of a command to the end of an existing text file without deleting its current contents, use the double greater-than symbol (>>). If the file does not already exist, MS-DOS creates a new file.

Syntax:

COMMAND >> FILENAME.EXT

Example: To append current memory status information to an ongoing log file named SYSINFO.TXT:

MEM >> SYSINFO.TXT

Additional Redirection Practices

  • Using File Paths: You can include drive letters and directory paths to save output to specific locations: 
    CHKDSK C: > C:\LOGS\CHECK.TXT
  • Discarding Output: If you want to suppress command output entirely instead of saving it, redirect the output to the NUL device: 
    COPY FILE.DAT A:\ > NUL
  • Standard Error Limitation: MS-DOS 6.22 standard command shell (COMMAND.COM) only redirects standard output (STDOUT). Error messages generated via standard error (STDERR) will generally continue to display on the screen rather than being captured in the file.