Shifting command output to the right

Question

Say I'm writing a .bashrc file to give me some useful information in my login terminals and I'm telling it to run the cal command (a nice one). How would I go about shifting the calendar produced to the right to match the formatting of the rest of my .bashrc "welcome message"?

Answer 1

cal | sed 's/^/     /'

Explanation

• cal |: pipe the output of cal to…
• sed 's/^/ /' sed, which will look for the start of lines ^, replacing with spaces. You can change the number of spaces here to match the required formatting.

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Edit

To preserve the highlighting of the current day from cal, you need to tell it to output "color" (highlighting) to the pipe. From man cal

   --color [when]
          Colorize output.  The when can be never, auto, or always.  Never will turn off coloriz‐
          ing  in  all  situations.  Auto is default, and it will make colorizing to be in use if
          output is done to terminal.  Always will allow colors to be outputed when  cal  outputs
          to pipe, or is called from a script.

N.B. there seems to be a typo in the manual; I needed a = for it to work. Hence, the final command is

cal --color=always | sed 's/^/     /'

Answer 2

cal | nl -bn

...will work because nl always indents input lines it doesn't number to equal the indent it would add to those it does. By default nl does not number -header or -footer sections of input, and only numbers -body lines. If you also tell it not to number -body lines it will number nothing at all and only insert indentation to every input line.

Use the -width and -separator switches to adjust the size of the indent.

---

cal; cal | nl -bn

---

    December 2015   
Su Mo Tu We Th Fr Sa
       1  2  3  4  5 
 6  7  8  9 10 11 12 
13 14 15 16 17 18 19 
20 21 22 23 24 25 26 
27 28 29 30 31       

           December 2015   
       Su Mo Tu We Th Fr Sa
              1  2  3  4  5 
        6  7  8  9 10 11 12 
       13 14 15 16 17 18 19 
       20 21 22 23 24 25 26 
       27 28 29 30 31       

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There is also:

cal | pr -to[num]

...where [num] is the number of spaces you want inserted at the head of each line. pr usually prints 66 lines per page, but the -t tells it to omit its header/footer inserts and just print input to output. The -offset margin switch is then used to insert as many spaces as are requested in [num] at the head of each output line:

cal; cal | pr -to10

---

    December 2015   
Su Mo Tu We Th Fr Sa
       1  2  3  4  5 
 6  7  8  9 10 11 12 
13 14 15 16 17 18 19 
20 21 22 23 24 25 26 
27 28 29 30 31       

              December 2015   
          Su Mo Tu We Th Fr Sa
                 1  2  3  4  5 
           6  7  8  9 10 11 12 
          13 14 15 16 17 18 19 
          20 21 22 23 24 25 26 
          27 28 29 30 31       

Answer 3

With paste:

cal | paste /dev/null -

paste pastes the lines of files together with TAB characters in between. Here we paste the empty file (/dev/null) with paste's stdin (-) which is the output of cal fed via a pipe.

Answer 4

You can use sed:

cal | sed -e 's/^/    /'

The above will indent the calendar by four spaces by inserting them at the start (^) of every line. You can change the indentation as you wish, or add other pieces of output.

If you want it perfectly right-aligned in any terminal you can use printf and stty with a more ugly loop:

read height width < <(stty size)
cal | while read line ; do printf "%${width}s" "$line" ; done

(stty size is non-standard but widely supported)

Answer 5

Here is example using ex:

ex +"%norm 20I " +%p -scq! <(cal)

Change 20 into number of required spaces. Using "%norm 20I " is more efficient than repeating many spaces with substitution - "%s/^/ /".