The fmemopen() function gives you a stdio FILE * object that refers to a buffer in memory. Replacing the open of test.jpg with a single call to fmemopen solves half the problem

fmemopen()函数提供了一个stdioFILE *对象，该对象表示内存中的一个缓冲区。

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In most cases, if what you want can be done with a higher-level library (stdio instead of raw reads and writes, for instance), you should do that; it gives you more insulation from possible quirks.

在大部分情况中，如果您希望可以使用更高级的库(举例来说，使用stdio，而不是原始的读写操作)，就应该这样做；这可以帮您更好地回避这些问题。

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Starting with IDS v10, ontape operations can now be directed to or from "standard in" or "standard out" (STDIO), thereby providing support for a wider range of options.

从IDSv10开始，ontape操作可以被定向到标准输入或标准输出设备(“standardin”或“standardout”，STDIO)，因此为很多选项提供了支持。

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Starting with IDS v10, ontape operations can now be directed to or from "standard in" or "standard out" (STDIO), thereby providing support for a wider range of options.

从IDSv10开始，ontape操作可以被定向到标准输入或标准输出设备(“standardin”或“standardout”，STDIO)，因此为很多选项提供了支持。

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