bash printf反斜杠，然后换行

Question

I am trying to create this from bash into ac header

#define XXXXX \

 "id title\n" \ 

 "1  developer\n" \

the script is 

FORMAT="  \"%-4s  %-32s\\\n"

printf "$FORMAT" "id" "title\\n\"" >> $FILE

printf "$FORMAT" "1" "Developer\\n\"" >> $FILE

the result would be

"id    title\n"                        \n  "1     Developer\n"                              \n

when I change FORMAT="%-4s %-32s \\\\ \\n"

I get

"id    title\n"                           \ 
"1     Developer\n"                       \ 

and gcc start to complain the extra space after \\

It seems that the \\\\ would be interpreted more than once if there is no space.

without using FORMAT="%-4s %-32s \\\\"

printf "$FORMAT" "id" "title\\n\"" >> $FILE

printf "\n" >> $FILE
...

Is there any better way to handle this?

Answer 1

使用十六进制转义序列：

FORMAT="%-4s %-32s \x5C\n"

Answer 2

shell treats double quote and single quote differently.

Don's use double quote here:

FORMAT="%-4s %-32s \\n"

Use single quote like this and avoid escaping:

FORMAT='%-4s %-32s \n'

OR for printing literal backslash and newline:

FORMAT='%-4s %-32s \\\n'