sh read command eats backslashes in input?

shell sh backslash
Jeremy Huiskamp picture Jeremy Huiskamp · May 29, 2009 · Viewed 17k times · Source

Perhaps easiest to explain with an example:

$ echo '\&|'
\&|
$ echo '\&|' | while read in; do echo "$in"; done
&|

It seems that the read command is interpreting the backslashes in the input as escapes and is removing them. I need to process a file line by line without changing its contents and I'm not sure how to stop read from being smart here. Any ideas?

Answer

Zsolt Botykai picture Zsolt Botykai · May 29, 2009

Accrding to: http://www.vias.org/linux-knowhow/bbg_sect_08_02_01.html :

-r
If this option is given, backslash does not act as an escape character. The backslash is considered to be part of the line. In particular, a backslash-newline pair may not be used as a line continuation.

It works on my machine.

$ echo '\&|' | while read -r in; do echo "$in"; done
\&|

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