如何在文本文件的两列之间放置逗号

Adi*_*tya -1 linux shell-script

这是我的文本文件:

0019121002313002316003135  
0057936000814000814003023  
0081638001519001523001176  
0090531001841001842002633  
0111210001515001518000912  
0115400001807001828001593
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我希望处理后的输出为:

0019121,002313,002316,003135
0057936,000814,000814,003023
0081638,001519,001523,001176
0090531,001841,001842,002633
0111210,001515,001518,000912
0115400,001807,001828,001593
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我该怎么做呢?

Kus*_*nda 5

$ sed -E 's/(.{7})(.{6})(.{6})(.{6})/\1,\2,\3,\4/' file
0019121,002313,002316,003135
0057936,000814,000814,003023
0081638,001519,001523,001176
0090531,001841,001842,002633
0111210,001515,001518,000912
0115400,001807,001828,001593
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也就是说,匹配组成新字段的每一行的位并在它们之间插入逗号。字段的匹配是使用.{7}.{6}取决于所需字段长度来完成的。