Using pipe character as a field separator

问题

I'm trying different commands to process csv file where the separator is the pipe | character.

While those commands do work when the comma is a separator, it throws an error when I replace it with the pipe:

awk -F[|] "NR==FNR{a[$2]=$0;next}$2 in a{ print a[$2] [|] $4 [|] $5 }" OFS=[|] file1.csv file2.csv

awk "{print NR "|" $0}" file1.csv

I tried, "|", [|], /| to no avail.

I'm using Gawk on windows. What I'm I missing?

回答1:

You tried "|", [|] and /|. /| does not work because the escape character is \, whereas [] is used to define a range of fields, for example [,-] if you want FS to be either , or -.

To make it work "|" is fine, are you sure you used it this way? Alternativelly, escape it --> \|:

$ echo "he|llo|how are|you" | awk -F"|" '{print $1}'
he
$ echo "he|llo|how are|you" | awk -F\| '{print $1}'
he
$ echo "he|llo|how are|you" | awk 'BEGIN{FS="|"} {print $1}'
he

But then note that when you say:

print a[$2] [|] $4 [|] $5

so you are not using any delimiter at all. As you already defined OFS, do:

print a[$2], $4, $5

Example:

$ cat a
he|llo|how are|you
$ awk 'BEGIN {FS=OFS="|"} {print $1, $3}' a
he|how are

回答2:

Try to escape the |

echo "more|data"  | awk -F\| '{print $1}'
more

回答3:

You can escape the | as \|

$ cat test
hello|world
$ awk -F\| '{print $1, $2}' test
hello world

来源：https://stackoverflow.com/questions/27246584/using-pipe-character-as-a-field-separator