Let's suppose that you need to generate a NUL-delimited stream of timestamped filenames.

On Linux & Solaris I can do it with:

stat --printf '%.9Y %n\0' -- *

On BSD, I can get the same info, albeit delimited by newlines, with:

stat -f '%.9Fm %N' -- *

The man talks about a few escape sequences but the NUL byte doesn't seem supported:

If the % is immediately followed by one of n, t, %, or @, then a newline character, a tab character, a percent character, or the current file number is printed.

Is there a way to work around that?

CodePudding user response：

Unfortunately, stat out of the box does not offer this option, and so what you ask is not directly achievable.

However, you can easily implement the required functionality in a scripting language like Perl or Python.

#!/usr/bin/env python3

from pathlib import Path
from sys import argv

for arg in argv[1:]:
    print(
        Path(arg).stat().st_mtime,
        arg, end="\0")

Demo: https://ideone.com/vXiSPY

The demo exhibits a small discrepancy in the mtime which does not seem to be a rounding error, but the result could be different on MacOS (the demo platform is Debian Linux, apparently). If you want to force the result to a particular number of decimal places, Python has formatting facilities similar to those of stat and printf.

CodePudding user response：

With any command that can't produce NUL-terminated output, you can just wrap it in a function to call the command and then printf it's output with a terminating NUL instead of newline:

nulstat() {
    local fmt=$1 file
    shift
    for file in "$@"; do
        printf '%s\0' "$(stat -f "$fmt" "$file")"
    done
}

nulstat '%.9Fm %N' *

For example:

$ > foo

$ > $'foo\nbar'

$ nulstat '%.9Fm %N' foo* | od -c
0000000    1   6   6   3   1   6   2   5   3   6   .   4   7   7   9   8
0000020    0   1   4   0       f   o   o  \0   1   6   6   3   1   6   2
0000040    5   3   9   .   3   8   8   0   6   9   9   3   0       f   o
0000060    o  \n   b   a   r  \0
0000066

CodePudding user response：

Is there a way to work around that?

If all you need is to just replace all newlines with NULLs, then following tr should suffice

stat -f '%.9Fm %N' * | tr '\n' '\000'

Explanation: 000 is NULL expressed as octal value.