用awk提取文本

Question

I want to grep a file and extract the third part of this line

#define SIM_VERSION_COMPAT 1302

with awk. So I wrote:

grep "#define SIM_VERSION_COMPAT" global.h | awk '{ print $$3 }'

The result should be 1302 but I get nothing (blank).

Answer 1

无需使用grep和管道，您可以像这样使用awk：

awk '/#define SIM_VERSION_COMPAT/{print $3}' global.h

Answer 2

Just using grep :

$ grep -Po '(?<=#define SIM_VERSION_COMPAT )[0-9]+' global.h
1302

This uses positive lookbehind to match lines containing #define SIM_VERSION_COMPAT but only prints the digit string following.

Answer 3

[spatel@tc01 ~]$ echo "#define SIM_VERSION_COMPAT 1302" | awk '{ print $3 }'
1302

Answer 4

您也可以使用cut命令

grep "#define SIM_VERSION_COMPAT" temp.txt | cut -d" " -f 3