curl: read headers from file

Question

After the --dump-header writes a file, how to do read those headers back into the next request? I would like to read them from a file because there are a number of them. <

Answer 1

As answered by @dmitry-sutyagin, if your curl is at least version 7.55.0 you can use the @ notation to read headers from a file:

curl -H @headerfile.txt https://www.google.com/  # requires curl 7.55.0

If your curl is NOT 7.55.0 or newer, there's a useful hack:

• Use the option -K/--config , and put several -H/--header
  lines in the text file.

For instance:

1. curl --dump-header foo.txt https://www.google.com/
2. If necessary, dos2unix foo.txt

3. Convert the file to -H 'header' lines, manually or with a script:

   cat foo.txt |
     awk '$1 == "Set-Cookie:"' |
     perl -ne "chomp; next if /^\\s*\$/; if (/'/) { warn; next } print \"-H '\$_'\\n\";" |
     tee headerfile.txt
   

   This might output something like:

   -H 'Set-Cookie: 1P_JAR=2018-02-13-08; [...]'
   -H 'Set-Cookie: NID=123=n7vY1W8IDElvf [...]'
   

4. curl --config headerfile.txt https://www.google.com/