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How do I use shell variables in an awk script?
... v1.5
Using -v (The best way, most portable)
Use the -v option: (P.S. use a space after -v or it will be less portable. E.g., awk -v var= not awk -vvar=)
variable="line one\nline two"
awk -v var="$variable" 'BEGIN {print var}'
line one
line two
This should be compatible with most a...
How to hide the “back” button in UINavigationController?
Do you know how to hide the 'back' button in a UINavigationController?
Also, how to show it back, but I guess that's very similar to hiding it...
...
How do I get the day of the week with Foundation?
...
outputs current day of week as a string in locale dependent on current regional settings.
To get just a week day number you must use NSCalendar class:
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSDateComponents *comps = [gregorian co...
StackOverflow程序员推荐：每个程序员都应读的30本书 - 杂谈 - 清泛网 - 专...
...个价是对得起这本书的。
你还不确信么？那就读读第一版的前言或序言。网上有免费的电子版。-Antti Sykäri
4. 《C程序设计语言》
推荐数：774
这本书简洁易读，会教给你三件事：C 编程语言；如何像程序员一样思考；底...
How can I get a precise time, for example in milliseconds in Objective-C?
...meInterval is in seconds, but it uses the double to give you greater precision.
In order to calculate millisecond time accuracy, you can do:
// Get a current time for where you want to start measuring from
NSDate *date = [NSDate date];
// do work...
// Find elapsed time and convert to millisecon...
When is the thread pool used?
...derstanding of how node works isn't correct... but it's a common misconception, because the reality of the situation is actually fairly complex, and typically boiled down to pithy little phrases like "node is single threaded" that over-simplify things.
For the moment, we'll ignore explicit multi-pr...
Comment the interface, implementation or both?
...inciple as with code:
on interface, document the interface
on implementation, document the implementation specifics
Java specific: when documenting the implementation, use {@inheritDoc} tag to "include" javadocs from the interface.
For more information:
Official javadoc documentation
Some uno...
How to Deal with Temporary NSManagedObject instances?
...OTE: This answer is very old. See comments for full history. My recommendation has since changed and I no longer recommend using unassociated NSManagedObject instances. My current recommendation is to use temporary child NSManagedObjectContext instances.
Original Answer
The easiest way to do this ...
How to read a .xlsx file using the pandas Library in iPython?
...
I usually create a dictionary containing a DataFrame for every sheet:
xl_file = pd.ExcelFile(file_name)
dfs = {sheet_name: xl_file.parse(sheet_name)
for sheet_name in xl_file.sheet_names}
Update: In pandas version 0.21.0+ you will ...
Reading large text files with streams in C#
...ask of working out how to handle large files being loaded into our application's script editor (it's like VBA for our internal product for quick macros). Most files are about 300-400 KB which is fine loading. But when they go beyond 100 MB the process has a hard time (as you'd expect).
...