I tried running it in Vim (I have version 8.1.1401), with a regular bash script, and it didn't run the dangerous command. However, when I made a hard link to th

I tried running it in Vim (I have version 8.1.1401), with a regular bash script, and it didn't run the dangerous command. However, when I made a hard link to the same file, then it did run the dangerous command. My guess is that Vim defaults to writing a new file with the same name, but, if there is a hard-link pointing at the same file, then it has to actually modify the file in place. That is probably what bit you in the past (although I'm sure this behaviour is configurable somewhere). If you want to force bash to read the whole script into memory on startup, you can put the whole script inside a function, and then, on the last line of the file, call the function you just defined.