OpenBSD: modify .profile for PS1 and PAGER

[J65nko]

A small script to modify PS1 and PAGER

# ---------------------------------------------------------
 
# /.profile used to be a  hard link to /root/.profile so only one needed
# to be modified
# Not true anymore :

#  ls -il /.profile /root/.profile 
#   24 -rw-r--r--  1 root  wheel  411 Jan 15 22:33 /.profile
# 4182 -rw-r--r--  1 root  wheel  440 Jan 18 01:13 /root/.profile

PROFILES="/.profile /root/.profile /etc/skel/.profile"

echo Modifying PS1 in ${PROFILES}

for file in $PROFILES ; do
    echo "$0: adding prompt to: $file"
    cat <<-END >>$file

        # --- prompt
        # j65nko@zeno[/home/j65nko/] 
        #  \u   @ \h [    \w       ]

        PS1="\u@\h[\w]"
        export PS1
        export PAGER=/usr/bin/less
END
done

The script uses the here document construct. From the OpenBSD (k)sh man page:

     << marker
             After reading the command line containing this kind of redirec-
             tion (called a ``here document''), the shell copies lines from
             the command source into a temporary file until a line matching
             marker is read.  When the command is executed, standard input is
             redirected from the temporary file.  If marker contains no quoted
             characters, the contents of the temporary file are processed as
             if enclosed in double quotes each time the command is executed,
             so parameter, command, and arithmetic substitutions are per-
             formed, along with backslash (`\') escapes for `$', ``', `\', and
             `\newline'.  If multiple here documents are used on the same com-
             mand line, they are saved in order.

     <<- marker
             Same as <<, except leading tabs are stripped from lines in the
             here document.

The marker used is '-END' so the leading tabs will be stripped.
You only have to use this when you want the here document to align nicely inside a loop like here.
Be aware that this only strips leading tabs and not leading spaces.

You can verify with cat whether there are really tabs and not spaces

$ cat -nt
    [snip] 
    15  for file in $PROFILES ; do
    16      echo "$0: adding prompt to: $file"
    17      cat <<-END >>$file
    18  
    19  ^I# --- prompt
    20  ^I# j65nko@zeno[/home/j65nko/] 
    21  ^I#  \u   @ \h [    \w       ]
    22  
    23  ^IPS1="\u@\h[\w]"
    24  ^Iexport PS1
    25  ^Iexport PAGER=/usr/bin/less
    26  END
    27  done

The CNTRL-I's (^I) proves that there are indeed leading tabs.

If you past the scirpt, then those tabs usually disappear:

$ cat -net pasted
     1  $
     2  for file in $PROFILES ; do$
     3      echo "$0: adding prompt to: $file"$
     4      cat <<-END >>$file$
     5  $
     6          # --- prompt$
     7          # j65nko@zeno[/home/j65nko/] $
     8          #  \u   @ \h [    \w       ]$
     9  $
    10          PS1="\u@\h[\w]"$
    11          export PS1$
    12          export PAGER=/usr/bin/less$
    13  END$

The .profile in the "/etc/skel" directory usually will be copied into the home directory of each user account.

# ls -l /etc/skel 
-rw-r--r--  1 root  wheel   22 Jan 15 22:33 .Xdefaults
-rw-r--r--  1 root  wheel  773 Jan 15 22:33 .cshrc
-rw-r--r--  1 root  wheel  398 Jan 15 22:33 .login
-rw-r--r--  1 root  wheel  113 Jan 15 22:33 .mailrc
-rw-r--r--  1 root  wheel  265 Jan 18 05:02 .profile
drwx------  2 root  wheel  512 Jan 15 22:33 .ssh

By customizing this file and/or the others, before creating user accounts you save time and efforts. Proactive laziness

[TerryP]

My way of being lazy, is simply called git.