有用的命令

cat << EOF > 1.txt 
1
2
3
EOF

cat << EOF > 2.txt 
1
3
3
EOF

2c2
< 2
---
> 3

vimdiff 1.txt 2.txt

timeout 1.1s ./1.out < in > out

/usr/bin/time  2.out < in
	Command being timed: "2.out"
	User time (seconds): 0.00 <- 执行的时间
	System time (seconds): 0.00  <- 执行的时间
	Percent of CPU this job got: 80%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.00
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 10032 <- 占用的最大内存
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 168
	Voluntary context switches: 1
	Involuntary context switches: 0
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0

ulimit -v 131072

TODO