Function explanation
int byteArrayBeforeWriteProc(char *src, int srcLen,char *des, int &desLen)
{
if (srcLen >= 0 && des != nullptr && desLen >= srcLen + 1) {
memcpy(des, src, srcLen);
des[srcLen] = '\0';
desLen = srcLen + 1;
return 0;
}
return -1; // 处理失败的情况
}
The function of this function is to copy the contents of one character array src to another character array des, and set the length of des to the length of src plus 1 after the copy is completed.
The specific steps are as follows:
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First, determine whether the incoming parameters are legal. It is required that srcLen must be greater than or equal to 0, des cannot be a null pointer, and desLen must be greater than or equal to srcLen+1. If these conditions are not met, -1 is returned to indicate processing failure.
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If the parameters passed in are legal, use the memcpy function to copy the contents of the src array to the des array. The memcpy function is a function in the C/C++ standard library and is used to copy the contents of one memory to another memory.
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After the copy is completed, add a '\0' character at the end of the des array to indicate the end of the string.
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Finally, set desLen to srcLen+1, indicating the length of the des array after copying.
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The return value is 0, indicating successful processing.
If the passed-in parameter is illegal (for example, srcLen is less than 0, des is a null pointer, or desLen is less than srcLen+1), -1 is returned, indicating that the processing failed.