shell实现str.replace更改日期格式

替换所有

echo ${MESSAGE//e/E}

替换第一个

echo ${MESSAGE/e/E}

Code：

$ MESSAGE="Develop a passion for learning. If you do, you will never cease to grow."
$ echo ${MESSAGE}
Develop a passion for learning. If you do, you will never cease to grow.

# Replace part of the text.
# Replace "passion" with "desire":
$ echo ${MESSAGE/passion/desire}
Develop a desire for learning. If you do, you will never cease to grow.

# Remove part of the text.
# Here, remove "passion":
$ echo ${MESSAGE/passion}
Develop a for learning. If you do, you will never cease to grow.

# Replace the first match in the text.
# Here, "e" becomes "E":
$ echo ${MESSAGE/e/E}
DEvelop a passion for learning. If you do, you will never cease to grow.
$ 

# Replace all matches in the text, by adding an extra slash (/).
# Here, all "e" become "E":
$ echo ${MESSAGE//e/E}
DEvElop a passion for lEarning. If you do, you will nEvEr cEasE to grow.

替换日期

2020-11-16  2020/11/16

$ echo ${MESSAGE//e/E}

$ date_str='2020-11-16'

$ echo ${date_str//-/\}
2020/11/16

 

参考

https://www.shellscript.sh/tips/pattern-substitution/