[SOLVED] awk: remove the last character in the file
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The idea is to use a record (line) separator consisting of a comma, optional whitespace, and one or more newlines. Using the automatic variable RT provided by GNU awk, we retain the record separators; we only output it just before the next record. When all records have been output, the comma (if any) is stripped from the final record separator, and the final separator is output.
The end result is that the file stays exactly the same, except when there is a final comma followed by (optional whitespace) and at least one newline; then the comma is stripped away.
Note that if there is no newline after the final comma, i.e. the comma is the last character in the file (except for optional spaces and tabs), it is not stripped. If you suspect you may have such files, better use a slightly more complicated variant that handles that case too:
The idea is to use a record (line) separator consisting of a comma, optional whitespace, and one or more newlines. Using the automatic variable RT provided by GNU awk, we retain the record separators; we only output it just before the next record. When all records have been output, the comma (if any) is stripped from the final record separator, and the final separator is output.
The end result is that the file stays exactly the same, except when there is a final comma followed by (optional whitespace) and at least one newline; then the comma is stripped away.
Note that if there is no newline after the final comma, i.e. the comma is the last character in the file (except for optional spaces and tabs), it is not stripped. If you suspect you may have such files, better use a slightly more complicated variant that handles that case too:
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