使用awk从文件中提取段

Question

我有一个文件，我需要根据另一个文件中给出的字符范围提取片段。我想用awk命令来做。

文件一个看起来像这样（单行）：

AATTGTGAAGGTAGATGGCTCGCTCCGCGGCGGGGCGCGCGCGCGCGCGCGGGCTCGCTATATAGAGATATATGCGCGCGGCGCGCGGCGCGCGCGGCGCGCGCGTATATATATAGGCGCGCGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAAAAAAAAAAAAAAAAAAAAAAAAATTTTTTTTTTTTTTTTTTTTTTTTTTTTTTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGCCCCCCCCCCCCCC

第二个文件如下所示：

5 10
13 20
22 24

，输出为：

GTGAAG
AGATGGCT
GCT

Answer 1

这个单行将解决您的问题：

awk 'BEGIN{getline sequence < "first_file"} {print substr(sequence, $1, $2 - $1 + 1) }' second_file

说明：此脚本使用sequence函数从名为first_file的文件中读取字符串getline（将其调整为实际文件名）。然后，对于第二个文件的每一行（包含处理范围），它使用substr函数提取必要的子字符串。 substr接受三个参数：字符串（sequence），位置（$1）和长度（$2 - $1 + 1）。

Answer 2

Nya 为您提供了awk解决方案，此处是基于coreutils的解决方案。

<强>字符串

AATTGTGAAGGTAGATGGCTCGCTCCGCGGCGGGGCGCGCGCGCGCGCGCGGGCTCGCTATATAGAGATATATGCGCGCGGCGCGCGGCGCGCGCGGCGCGCGCGTATATATATAGGCGCGCGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAAAAAAAAAAAAAAAAAAAAAAAAATTTTTTTTTTTTTTTTTTTTTTTTTTTTTTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGCCCCCCCCCCCCCC

<强> offlen

5 10
13 20
22 24

您可以获得所需的输出：

while read off len; do cut -c${off}-${len} string; done < offlen

输出：

GTGAAG
AGATGGCT
GCT