biaocy/快速生成随机数.md

## 快速生成随机数.md

      
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              快速生成随机数.md
            
          
利用 /dev/urandom 快速生成随机 hexadecimal

hexdump -v -e '4/1 "%02x" "\t" "%02x" "\n"' /dev/urandom

快速生成10000个随机数字

hexdump -v -e '4/1 "%02x""\n"' /dev/urandom | awk '{ print strtonum("0x" $0) }' | head -n 10000

快速生成MySQL csv文件，包含十万行数据
假设插入的两个字段(number, name)

hexdump -v -e '4/1 "%02x""\n"' /dev/urandom | awk -v OFS=',' '{ print strtonum("0x" $0), "\"name-" NR "\"" }' | head -n 100000 > data.csv
导入数据库:
mysql -p -D <db name> -e '
load data local infile "<csv file path>"
into table `<table name>`
fields terminated by ","
enclosed by "\""
lines terminated by "\n"
(number, name)
'