Question

如何打印与特定图案和之前的线匹配的线？

我确实有这样的转储：

Apple:Orange=9942501133;
Fault Code 9
Apple:Orange=9942501144;
Fault Code 9
Apple:Orange=9942501155;
Apple:Orange=9942501166;
Apple:Orange=9942501177;
Fault Code 9
Apple:Orange=9942501188;
Apple:Orange=9942501199;
Apple:Orange=9942501200;
Apple:Orange=9942501211;
Fault Code 9
Apple:Orange=9942501222;

输出结果为“故障代码9”的上述行，其中包含故障代码9：

Apple:Orange=9942501133;
Fault Code 9
Apple:Orange=9942501144;
Fault Code 9
Apple:Orange=9942501177;
Fault Code 9
Apple:Orange=9942501211;
Fault Code 9

Answer 1

# grep -B1 ^Fault log.txt

-B开关的意思是“之前”。

Answer 2

这应该可以胜任。

cat yourfile | perl -e 'while(<STDIN>) { if(/Fault Code 9/) { print $prev; } $prev=$_; }'

在纯shell中：

cat yourfile | while read line
do
  if [ "$line" == "Fault Code 9" ]; then
    echo "$prev"
  fi
  prev=$line
done

Answer 3

GAWK：

/^Fault Code 9/ {
  print s
  print $0
}

{
  s = $0
}

Answer 4

tr -d '\n' <yourfile | grep -E -o '[^; ]+; *Fault Code 9' | sed 's/;.*$//'

Answer 5

grep -B1 'Fault Code 9' filename.txt

如果下一行以特定单词开头，则应打印前一行

5 个答案: