How to get an environment variable in Go?
In Go lang, how to get an environment variable?
To get an environment variable (e.g. “VAR”) in GO:
import "os"
import "fmt"
fmt.Println("VAR:", os.Getenv("VAR"))
Similar Posts
How to capture camera photo/video using MPlayer on Linux?
ByEric MaHow to capture camera photo/video using MPlayer on Linux? You can watch the video from the camera by MPlayer: # mplayer tv:// Note that you need the root privilege to play the tv://. You can use mplayer to capture photos by: # mplayer -vo png -frames 3 tv:// If will store files 0000000{1..3}.png in the…
g++: sorry, unimplemented: non-trivial designated initializers not supported
ByQ Ag++ (version g++ (GCC) 4.8.1 20130603 (Red Hat 4.8.1-1)) report: $ g++ -std=c++11 solution.cpp -o sol solution.cpp: In function ‘int main()’: solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported Stat init_stat {.depth = 0, .moves = tv, .vec = init}; ^ solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers…
How to force a checkpointing of metadata in HDFS?
ByEric MaHDFS SecondaraNameNode log shows 2017-08-06 10:54:14,488 ERROR org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode: Exception in doCheckpoint java.io.IOException: Inconsistent checkpoint fields. LV = -63 namespaceID = 1920275013 cTime = 0 ; clusterId = CID-f38880ba-3415-4277-8abf-b5c2848b7a63 ; blockpoolId = BP-578888813-10.6.1.2-1497278556180. Expecting respectively: -63; 263120692; 0; CID-d22222fd-e28a-4b2d-bd2a-f60e1f0ad1b1; BP-622207878-10.6.1.2-1497242227638. at org.apache.hadoop.hdfs.server.namenode.CheckpointSignature.validateStorageInfo(CheckpointSignature.java:134) at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.doCheckpoint(SecondaryNameNode.java:531) at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.doWork(SecondaryNameNode.java:395) at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode$1.run(SecondaryNameNode.java:361) at org.apache.hadoop.security.SecurityUtil.doAsLoginUserOrFatal(SecurityUtil.java:415) at org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.run(SecondaryNameNode.java:357) It seems the checkpoint…
How to configure Linux to use the scanner in an HP all-in-one printer?
ByEric MaHow to configure Linux to use the scanner (not only the printer) in an HP all-in-one printer? The OS is Fedora 22 and the connection between the HP all-in-one printer and the PC is through wireless. The printer is working well. You can check this post for configuring the printer and scanner of HP All-In-One…
encfs on CentOS 6 can’t mount as normal user
ByEric MaOn CentOS 7, using a normal user, encfs works just well. On CentOS 6, using the root user, encfs works. However, the problem is, on CentOS 6, using a normal user account, encfs does not work as on CentOS 7. $ encfs -s ~/t/.enc ~/t/enc EncFS Password: fuse: failed to exec fusermount: Permission denied fuse…
PUMA: A MapReduce Benchmark Suite
ByEric MaMapReduce is a well-known programming model designed for generating and processing large data. There are various MapReduce implementations. One widely known and used one may be Hadoop. Benchmarking MapReduce frameworks gets to be important. Faraz Ahmad et al. developed a benchmark suite: PUMA MapReduce Benchmark. During our work on MapReduce, we developed a benchmark suite…