3.2.2 Checking Files Out and In

Once your source code is under SCCS control, you use SCCS for two main tasks: to check out a file so that you can edit it, and to check in a file you have finished editing.

Check out a file with the sccs edit command. For example:

demo% sccs edit computepts.f

SCCS then makes a writable copy of computepts.f in the current directory, and records your login name. Other users cannot check the file out while you have it checked out, but they can find out who has checked it out.

When you have completed your editing, check in the modified file with the sccs delget command. For example:

demo% sccs delget computepts.f

This command causes the SCCS system to:

• Make sure that you are the user who checked out the file by comparing login names

• Prompt for a comment from you on the changes

• Make a record of what was changed in this editing session

• Delete the writable copy of computepts.f from the current directory

• Replace it by a read-only copy with the SCCS keywords expanded

The sccs delget command is a composite of two simpler SCCS commands, delta and get. The delta command performs the first three tasks in the list above; the get command performs the last two tasks.