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How to loop over files in directory and change path and add suffix to filename
...le of notes first: when you use Data/data1.txt as an argument, should it really be /Data/data1.txt (with a leading slash)? Also, should the outer loop scan only for .txt files, or all files in /Data? Here's an answer, assuming /Data/data1.txt and .txt files only:
#!/bin/bash
for filename in /Data/*...
Can I list-initialize a vector of move-only type?
...nitializer list elements in the current revision of the language.
Specifically, we have:
typedef const E& reference;
typedef const E& const_reference;
typedef const E* iterator;
typedef const E* const_iterator;
const E* begin() const noexcept; // first element
const E* end() const noexce...
SQL join: selecting the last records in a one-to-many relationship
...
This is an example of the greatest-n-per-group problem that has appeared regularly on StackOverflow.
Here's how I usually recommend solving it:
SELECT c.*, p1.*
FROM customer c
JOIN purchase p1 ON (c.id = p1.customer_id)
LEFT OUTER JOIN purchase p2 ON (...
How do you use bcrypt for hashing passwords in PHP?
...d salts (bcrypt REQUIRES salts) and you can be sure that an attack is virtually unfeasible without either ludicrous amount of funds or hardware.
bcrypt uses the Eksblowfish algorithm to hash passwords. While the encryption phase of Eksblowfish and Blowfish are exactly the same, the key schedule pha...
Extracting numbers from vectors of strings
...ion is an indirect way of getting to the solution. If you want to retrieve all the numbers, I recommend gregexpr:
matches <- regmatches(years, gregexpr("[[:digit:]]+", years))
as.numeric(unlist(matches))
If you have multiple matches in a string, this will get all of them. If you're only intere...
Apache Spark: map vs mapPartitions?
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I'm seeing the opposite -- even with very small operations, its faster to call mapPartitions and iterate than call map. I am assuming that this is just the overhead of starting the language engine that will process the map task. (I'm in R, which may have more startup...
How do you assert that a certain exception is thrown in JUnit 4 tests?
How can I use JUnit4 idiomatically to test that some code throws an exception?
34 Answers
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How to get first character of string?
... chartAt(0) in Firefox as of Firefox 71. See for yourself here: jsperf.com/testing-the-first-character-in-a-string/1
– Stephen M Irving
Dec 16 '19 at 21:54
1
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OceanBase使用libeasy原理源码分析：客户端 - 数据库(内核) - 清泛网 - 专...
...端》，作为客户端使用时，会涉及到一些数据结构，easy_session_t, easy_client_t, easy_hash_t, easy_hash_list_t等。
easy_session_t用来封装一个要发出去的请求，easy_client_t用来封装一个TCP连接的发起端，easy_hash_t是一个哈希表，easy_hash_list_t是...
Creating JSON on the fly with JObject
For some of my unit tests I want the ability to build up particular JSON values (record albums in this case) that can be used as input for the system under test.
...