Catching Specific Errors, Ignoring Errors, Catching Interrupts, and Catching All Exceptions

catch all ":unlet" errors by a > :catch /^Vim(unlet):/ or all errors for misspelled command names by a > :catch /^Vim:E492:/ Some error messages may be produced by different commands: > :function nofunc and > :delfunction nofunc both produce the error message > E128: Function name must start with a capital: nofunc which is converted inside try conditionals to an exception > Vim(function):E128: Function name must start with a capital: nofunc or > Vim(delfunction):E128: Function name must start with a capital: nofunc respectively. You can catch the error by its number independently on the command that caused it if you use the following pattern: > :catch /^Vim(\a\+):E128:/ Some commands like > :let x = novar produce multiple error messages, here: > E121: Undefined variable: novar E15: Invalid expression: novar Only the first is used for the exception value, since it is the most specific one (see |except-several-errors|). So you can catch it by > :catch /^Vim(\a\+):E121:/ You can catch all errors related to the name "nofunc" by > :catch /\<nofunc\>/ You can catch all Vim errors in the ":write" and ":read" commands by > :catch /^Vim($write\|read$):E\d\+:/ You can catch all Vim errors by the pattern > :catch /^Vim$(\a\+)$\=:E\d\+:/ < *catch-text* NOTE: You should never catch the error message text itself: > :catch /No such variable/ only works in the English locale, but not when the user has selected a different language by the |:language| command. It is however helpful to cite the message text in a comment: > :catch /^Vim(\a\+):E108:/ " No such variable IGNORING ERRORS *ignore-errors* You can ignore errors in a specific Vim command by catching them locally: > :try : write :catch :endtry But you are strongly recommended NOT to use this simple form, since it could catch more than you want. With the ":write" command, some autocommands could be executed and cause errors not related to writing, for instance: > :au BufWritePre * unlet novar There could even be such errors you are not responsible for as a script writer: a user of your script might have defined such autocommands. You would then hide the error from the user. It is much better to use > :try : write :catch /^Vim(write):/ :endtry which only catches real write errors. So catch only what you'd like to ignore intentionally. For a single command that does not cause execution of autocommands, you could even suppress the conversion of errors to exceptions by the ":silent!" command: > :silent! nunmap k This works also when a try conditional is active. CATCHING INTERRUPTS *catch-interrupt* When there are active try conditionals, an interrupt (CTRL-C) is converted to the exception "Vim:Interrupt". You can catch it like every exception. The script is not terminated, then. Example: > :function! TASK1() : sleep 10 :endfunction :function! TASK2() : sleep 20 :endfunction :while 1 : let command = input("Type a command: ") : try : if command == "" : continue : elseif command == "END" : break : elseif command == "TASK1" : call TASK1() : elseif command == "TASK2" : call TASK2() : else : echo "\nIllegal command:" command : continue : endif : catch /^Vim:Interrupt$/ : echo "\nCommand interrupted" : " Caught the interrupt. Continue with next prompt. : endtry :endwhile You can interrupt a task here by pressing CTRL-C; the script then asks for a new command. If you press CTRL-C at the prompt, the script is terminated. For testing what happens when CTRL-C would be pressed on a specific line in your script, use the debug mode and execute the |>quit| or |>interrupt| command on that line. See |debug-scripts|. CATCHING ALL *catch-all* The commands > :catch /.*/ :catch // :catch catch everything, error exceptions, interrupt exceptions and exceptions explicitly thrown by the |:throw| command. This is useful at the top

This section provides examples of how to catch specific Vim errors using regular expressions in `:catch` statements, including examples for catching `:unlet` errors, misspelled commands, and errors related to specific function names or commands like `:write` and `:read`. It warns against catching error message text due to localization issues. It also explains how to ignore errors using `try-catch` blocks or the `:silent!` command, emphasizing the importance of catching only the intended errors. Additionally, it covers how to catch interrupts (CTRL-C) as exceptions and provides an example of handling them in a script. Finally, it mentions that `:catch /.*/`, `:catch //`, and `:catch` can catch all types of exceptions, including errors, interrupts, and exceptions thrown by the `:throw` command.