ed: Diagnostics
9 Diagnostics
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When an error occurs, if 'ed''s input is from a regular file or here
document, then it exits, otherwise it prints a '?' and returns to command
mode. An explanation of the last error can be printed with the 'h' (help)
command.
If the 'u' (undo) command occurs in a global command list, then the
command list is executed only once.
Attempting to quit 'ed' or edit another file before writing a modified
buffer results in an error. If the command is entered a second time, it
succeeds, but any changes to the buffer are lost.
Info Catalog
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