RGBCube/uutils-coreutils
1
Fork 0
mirror of https://github.com/RGBCube/uutils-coreutils synced 2025-07-28 11:37:44 +00:00
Code Issues Activity

dd: pad partial record with spaces in some cases

Browse source 
If `conv=block,sync` command-line arguments are given and there is at
least one partial record read from the input (for example, if the
length of the input is not divisible by the value of the `ibs`
argument), then output an extra block of `cbs` spaces.

For example, no extra spaces are printed in this example because the
input is of length 10, a multiple of `ibs`:

    $ printf "012\nabcde\n" \
    > | dd ibs=5 cbs=5 conv=block,sync status=noxfer \
    > && echo $
    012  abcde$
    2+0 records in
    0+1 records out

But in this example, 5 extra spaces are printed because the length of
the input is not a multiple of `ibs`:

    $ printf "012\nabcdefg\n" \
    > | dd ibs=5 cbs=5 conv=block,sync status=noxfer \
    > && echo $
    012  abcde     $
    2+1 records in
    0+1 records out
    1 truncated record

The number of spaces printed is the size of the conversion block,
given by `cbs`.
This commit is contained in:
Jeffrey Finkelstein 2022-02-17 18:58:25 -05:00
parent f11ac4b076
commit 9f367b72e6
2 changed files with 57 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

25
tests/by-util/test_dd.rs
View file

@ -1,4 +1,4 @@
// spell-checker:ignore fname, tname, fpath, specfile, testfile, unspec, ifile, ofile, outfile, fullblock, urand, fileio, atoe, atoibm, availible, behaviour, bmax, bremain, btotal, cflags, creat, ctable, ctty, datastructures, doesnt, etoa, fileout, fname, gnudd, iconvflags, nocache, noctty, noerror, nofollow, nolinks, nonblock, oconvflags, outfile, parseargs, rlen, rmax, rposition, rremain, rsofar, rstat, sigusr, sigval, wlen, wstat abcdefghijklm abcdefghi
// spell-checker:ignore fname, tname, fpath, specfile, testfile, unspec, ifile, ofile, outfile, fullblock, urand, fileio, atoe, atoibm, availible, behaviour, bmax, bremain, btotal, cflags, creat, ctable, ctty, datastructures, doesnt, etoa, fileout, fname, gnudd, iconvflags, nocache, noctty, noerror, nofollow, nolinks, nonblock, oconvflags, outfile, parseargs, rlen, rmax, rposition, rremain, rsofar, rstat, sigusr, sigval, wlen, wstat abcdefghijklm abcdefghi nabcde nabcdefg abcdefg
use crate::common::util::*;
@ -1102,3 +1102,26 @@ fn test_truncated_record() {
fn test_outfile_dev_null() {
new_ucmd!().arg("of=/dev/null").succeeds().no_stdout();
}
#[test]
fn test_block_sync() {
new_ucmd!()
.args(&["ibs=5", "cbs=5", "conv=block,sync", "status=noxfer"])
.pipe_in("012\nabcde\n")
.succeeds()
// blocks: 1 2
.stdout_is("012 abcde")
.stderr_is("2+0 records in\n0+1 records out\n");
// It seems that a partial record in is represented as an
// all-spaces block at the end of the output. The "1 truncated
// record" line is present in the status report due to the line
// "abcdefg\n" being truncated to "abcde".
new_ucmd!()
.args(&["ibs=5", "cbs=5", "conv=block,sync", "status=noxfer"])
.pipe_in("012\nabcdefg\n")
.succeeds()
// blocks: 1 2 3
.stdout_is("012 abcde ")
.stderr_is("2+1 records in\n0+1 records out\n1 truncated record\n");
}