LinuxQuestions.org - umask chmod??

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- - umask chmod?? (https://www.linuxquestions.org/questions/linux-newbie-8/umask-chmod-276398/)

my umask shows the following:

> umask
0022

my question is when I create a file

> touch file; ls -al

the file permision is 644??

I thought the file should be permission 777-022 = 755 ??

The execute permissions are only given to execute-capable files. It makes no sense to try and run a file you've only touch'ed. It's the same thing with text editors like vi, emacs, nano, etc. You're creating a text file, and it makes no sense to execute a text file. The exception would be scripts, but there's no way the text editor can know if you're writing plain text or a script. So, I suspect the decision to set file attributes is embedded in the program somewhere. If you want to see an example of what you were expecting, do this:

in file hello.c:

Code:

#include <stdio.h>



int main( int argc, char *argv[] )

{

  printf( "Hello world.\n" );

  return 0;

}

from a prompt:

Code:

gcc -o hello hello.c

ls -al

You'll see the hello binary listed with 755 permissions.

now this is a good question (lke you care what i think ;) )
traditionally standard utils like touch when they create files create them 0666
here is some code from an ancient unix V7 version of touch

Code:

 if( (fd = creat(name, 0666)) < 0)

                goto bad;

 close(fd);

from modern Linux coreutils-5.2.1

Code:

if (! no_create)

    {

      /* Try to open FILE, creating it if necessary.  */

      fd = open (file, O_WRONLY | O_CREAT | O_NONBLOCK | O_NOCTTY,

                S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);

S_IRUSR = 00400
S_IWUSER = 00200
and you can extrapolate the rest
so it's still the same 00666 as it's always been

default permissions are 666 for files and 777 for directories. umask is subtracted from those.