shell - 用另一个文件中指定的值替换字段

Question

我有一个文件，其中包含单词之间的映射。我必须引用该文件并将这些词替换为某些文件中的映射词。例如，下面的文件具有映射的单词表

1.12.2.4               1
1.12.2.7               12
1.12.2.2               5
1.12.2.4               4
1.12.2.6               67
1.12.2.12              5

我会有很多包含这些关键词的文件(1.12.2.*)。我想搜索这些关键词并将这些词替换为从此文件中获取的相应映射。如何在 shell 中执行此操作。假设一个文件包含以下几行说

The Id of the customer is 1.12.2.12. He is from Grg. 
The Name of the machine is ASB
The id is 1.12.2.4. He is from Psg.

执行脚本后，数字“1.12.2.12”和“1.12.2.4”应替换为 5 和 4(引用主文件)。谁能帮我吗？

Answer 1

使用 GNU awk 的一种方式:

awk 'FNR==NR { array[$1]=$2; next } { for (i in array) gsub(i, array[i]) }1' master.txt file.txt

结果:

The Id of the customer is 5. He is from Grg.
The Name of the machine is ASB
The id is 4. He is from Psg.

将输出保存到文件:

awk 'FNR==NR { array[$1]=$2; next } { for (i in array) gsub(i, array[i]) }1' master.txt file.txt > name_of_your_output_file.txt

说明:

FNR==NR { ... }   # FNR is the current record number, NR is the record number
                  # so FNR==NR simply means: "while we process the first file listed
                  # in this case it's "master.txt"
array[$1]=$2      # add column 1 to an array with a value of column 2
next              # go onto the next record

{                 # this could be written as: FNR!=NR
                  # so this means "while we process the second file listed..."
for (i in array)  # means "for every element/key in the array..."
gsub(i, array[i]) # perform a global substitution on each line replacing the key
                  # with it's value if found
}1                # this is shorthand for 'print'

添加词边界使匹配更加严格:

awk 'FNR==NR { array[$1]=$2; next } { for (i in array) gsub("\\<"i"\\>", array[i]) }1' master.txt file.txt