If I have two files, tmp.txt and tmp.pdf, one large and one small, when I type ls -al tmp.* everything is nicely right justified and I get this output
-rw-r--r-- 1 simon simon 615316 Oct 17 20:55 tmp.pdf
-rw-r--r-- 1 simon simon 0 Oct 17 20:55 tmp.txt
For a reason that doesn't matter, I want to be able to write the output of two separate ls -al commands to a file, then cat the file and obtain the same output. But of course, if I do this:
ls -al tmp.txt > foo
ls -al tmp.pdf >> foo
and then cat foo, I get this
-rw-r--r-- 1 simon simon 0 Oct 17 20:55 tmp.txt
-rw-r--r-- 1 simon simon 615316 Oct 17 20:55 tmp.pdf
Is there a way of mimicking the justified output that ls -al produces? Obviously, I can use wc -c tmp.pdf etc to figure out which output is largest, but how would I translate that information into code that would put the requisite number of spaces before the 0 in the first line? Thanks very much for any suggestions.
Yes. Just use column
$ (ll tmp.small; ll tmp.big) | column -t -rw-r--r-- 1 myuser myuser 0 Oct 18 11:24 tmp.small -rw-r--r-- 1 myuser myuser 113616 Oct 18 11:42 tmp.big
However if your file names contain spaces then those names won't be printed correctly. If your column supports the -l option then the simplest fix is to change to column -t -l 9 to limit the total number of columns to 9. Another workaround is to use stat to simulate ls output
$ ( > stat --printf="%A\t%h\t%U\t%G\t%s\t%y\t%n\n" "tmp with space.txt" > stat --printf="%A\t%h\t%U\t%G\t%s\t%y\t%n\n" tmp.small > stat --printf="%A\t%h\t%U\t%G\t%s\t%y\t%n\n" tmp.big > ) | column -t -s $'\t' -rw-r--r-- 1 myuser myuser 1307 2020-10-18 12:08:45.360000000 +0700 tmp with space.txt -rw-r--r-- 1 myuser myuser 0 2020-10-18 11:24:21.650000000 +0700 tmp.small -rw-r--r-- 1 myuser myuser 113616 2020-10-18 11:42:04.150000000 +0700 tmp.big
Files with tabs or newlines in their names still don't work though. You may try to change the delimiter to null with stat --printf="%A\0%h\0%U\0%G\0%s\0%Y\0%n\n" tmp* | column -t -s $'\0' -l 9 but somehow my column doesn't recognize \0 as the delimiter. Not sure about other columns versions, just try it on your PC and see