shell-whiz-toolkit/awk/README.md

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## awk
<br>
### data manipulation
<br>
* print elements in the column 3 that has the word "good" in the other columns
```
$ awk '/good/ { print $3 }' inventory
```
* syntax:
```
$ awk -f {PROGRAM FILE} FILENAME
```
* awk program is:
```
PATTERN{
ACTION 1
ACTION 2
ACTION 3
}
```
with
```
. (Dot) Match any character
* Match zero or more character
^ Match beginning of line
$ Match end of line
\ Escape character following
[ ] List
{ } Match range of instance
+ Match one more preceding
? Match zero or one preceding
| Separate choices to match
```
<br>
---
### if condition
<br>
```
if (condition)
{
Statement 1
Statement 2
Statement N
if condition is TRUE
}
else
{
Statement 1
Statement 2
Statement N
if condition is FALSE
}
```