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I need to check an SDHC card. Is there a tool for mac which checks the true size of a usb flash drive or sdhc card?

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What do you mean by "true size"? Base 2 vs Base 10 will report differently (Windows + OSX <=SL uses Base2; OSX > SL uses Base 10), which are you looking for...? –  nerdwaller Apr 17 '13 at 20:48

2 Answers 2

In finder, and in disk utility it does show the "true size", if you are referring to the advertised size, that is before formatting. The formatted size is usually a bit less then the unformatted.

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I believe that the df command (check man df for details in the Terminal) can help you. The mount point for your SDHC/USB should be under /Volumes.

You can also try to use diskutil list or hdiutil info | grep "block" and do a simple multiplication.

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I think you mean df, not du. "du" shows how much space a given file/directory uses, not the amount of free space. –  barrycarter Nov 9 '13 at 20:18
You're right, my error. Thank you for the correction! :) –  dezzeus Nov 22 '13 at 20:37

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