sh read command eats slashes in input?

问题:

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 slashes 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?

回答1:

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
\&|

回答2:

Use read -r, as per http://www.ss64.com/bash/read.html:

-r
If this option is given, backslash does not act as an escape character.