When I export my iMovie project to an mp4

File > Share > File (iirc)

And name it "Tacos w/ John" for example, the file created is "Tacos w: John.mp4"

But if I name it "PROJECT: Yi", it saves to "PROJECT/ Yi.mp4"


  • File names can’t have the forward slash character because that tells the file system to go to a directory (or folder). For example, example.com/stuff/files/file.mov looks for file.mov inside the “files” directory, which looks for the “files” directory inside the “stuff” directory on the example.com server. If you could have a file called “tacos w/ John.mp4”, the computer would think it’s suppose to look for the file “john.mp4” inside the “tacos w” directory. I’m not quite sure why it is changing the colon though. – RyDev Nov 11 '19 at 15:17
  • Is this on an HFS or on an APFS filesystem? Can you add the output of ls -l on these two files? – nohillside Nov 11 '19 at 15:19
  • @klanomath: what do you mean by "both reserved characters are the forward slash"? From the terminal, I can create files with colons in their names, and they are displayed (via "ls") with colons. If I create a file in another app (say TextEdit) and try to put a colon in its name, TextEdit and Finder will display it as a slash, but "ls" displays it as a colon. If I create a file in TextEdit with a slash in its name, "ls" displays it using a colon. So it seems to me that both are colons, not slashes. – John Palmieri Nov 11 '19 at 21:02
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    The colon thing seems to be a bug specific to Finder. You can, without problems, use colons in file names. The Finder just shows it as a slash, while it is in fact still a colon. – Bachsau Nov 11 '19 at 22:35
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    Unix APIs forbid slash in filenames, but allow colon; traditional Mac OS (pre-Mac-OS-X) APIs forbid colon, but allow slash. macOS uses a mix of these APIs, and so it has to swap characters back & forth depending on context to avoid the forbidden one. See this previous question, this SO question, and this USENEX paper. – Gordon Davisson Nov 12 '19 at 0:52

They are reserved characters. You can’t use them you need to think of a different delimiter. IE. Tacho-John.mp4

  • Well, the colon at least can be used. The forward slash is still confusing (but I'm pretty sure can't be in a file name) – theonlygusti Nov 11 '19 at 23:55

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