通过特定的定界符删除字符串 [英] Remove strings by a specific delimiter

问题描述

我的文件中没有几列，其中第二列带有:"定界符，我想删除第二列中的第一，第三和第四字符串，并将第二字符串保留在该列中.但是我有正常的定界符空间，所以我不知道.

I have few columns in a file, in which the second column has ":" delimiter and I would like to remove the first, third and fourth strings in the second column and left the second string in that column. But I have the normal delimiter space, so I have no idea.

input:

--- 22:16050075:A:G 16050075 A G
--- 22:16050115:G:A 16050115 G A
--- 22:16050213:C:T 16050213 C T
--- 22:16050319:C:T 16050319 C T
--- 22:16050527:C:A 16050527 C A

desired output:

--- 22 16050075 16050075 A G
--- 22 16050115 16050115 G A
--- 22 16050213 16050213 C T
--- 22 16050319 16050319 C T
--- 22 16050527 16050527 C A

Wrong:
cat df.txt | awk -F: '{print $1, $3, $6, $7, $8}'

--- 22 A
--- 22 G
--- 22 C
--- 22 C
--- 22 C

但是我做不正确. awk和sed命令可以做到吗?

but I can not do it right. can awk and sed command can do it?

谢谢.

推荐答案

只需将$2上与POSIX兼容的split()函数用作

Just use the POSIX compatible split() function on $2 as

awk '{split($2,temp,":"); $2=temp[2];}1' file
--- 16050075 16050075 A G
--- 16050115 16050115 G A
--- 16050213 16050213 C T
--- 16050319 16050319 C T
--- 16050527 16050527 C A

在分隔符:上拆分第2列，将$2值更新为所需元素(temp[2])，然后打印其余字段({}1根据FS并打印出来.)

Split the column 2 on de-limiter :, update the $2 value to the required element (temp[2]) and print the rest of the fields ({}1 re-constructs all individual fields based on FS and prints it).

建议使用多个定界符，因为它会更改各个字段的绝对位置，而split()使其易于保留位置并仅提取所需的值.

Recommend this over using multiple de-limiters, as it alters the absolute position of the individual fields, while split() makes it easy to retain the position and just extract the required value.

要更新要求添加新列，只需执行

For your updated requirement to add a new column, just do

awk '{split($2,temp,":"); $2=temp[1] FS temp[2];}1' file
--- 22 16050075 16050075 A G
--- 22 16050115 16050115 G A
--- 22 16050213 16050213 C T
--- 22 16050319 16050319 C T
--- 22 16050527 16050527 C A

---

或者，如果您具有GNU awk/gawk，则可以将其gensub()用于基于正则表达式的提取(使用POSIX字符类[[:digit]])作为

---

Alternatively if you have GNU awk/gawk you can use its gensub() for a regex (using POSIX character class [[:digit]]) based extraction as

awk '{$2=gensub(/^([[:digit:]]+):([[:digit:]]+).*$/,"\\1 \\2","g",$2);}1' file
--- 22 16050075 16050075 A G
--- 22 16050115 16050115 G A
--- 22 16050213 16050213 C T
--- 22 16050319 16050319 C T
--- 22 16050527 16050527 C A

gensub(/^([[:digit:]]+):([[:digit:]]+).*$/,"\\1 \\2","g",$2)部分仅捕获由:分隔的前两个字段，并带有捕获组\\1和\\2，并打印其余字段.

The gensub(/^([[:digit:]]+):([[:digit:]]+).*$/,"\\1 \\2","g",$2) part captures only the first two fields de-limited by : with the capturing groups \\1 and \\2 and printing the rest of the fields as such.

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