Use quote in diagnostics. Change many error format strings
from just `%s' to e.g., `error reading %s'.
(pipe_lines): Change type of parameter, n_lines, to uintmax_t.
Rewrite newline-counting loop to use memchr.
Remove that (redundant) first use.
Don't exit successfully just because --verbose was specified.
Pass 0, not EXIT_SUCCESS, as first argument to error; when that
parameter is 0, error does not exit.
(IF_READDIR_NEEDS_REWINDDIR): Remove.
(remove_cwd_entries): Rewrite to avoid IF_READDIR_NEEDS_REWINDDIR,
which was a bit weird because it couldn't be emulated by a function.
but the N lines (bytes) at the end of the file.
Include full-write.h, full-read.h, inttostr.h, quote.h.
Use quote() in diagnostics, rather than literal `' marks.
(copy_fd, elide_tail_bytes_pipe, elide_tail_bytes_file):
New functions.
(elide_tail_lines_pipe, elide_tail_lines_file): New functions.
(head_file): Reorganize so as to call head from only one place.
(main): Likewise, for head_file.
Handle new, undocumented option, --presume-input-pipe.
Handle negative line and byte counts.
(IF_READDIR_NEEDS_REWINDDIR): Define.
[! HAVE_WORKING_READDIR] (remove_cwd_entries): If readdir has just
returned NULL and there has been at least one successful unlink or
rmdir call since the opendir or previous rewinddir, then call
rewinddir and reiterate the loop.
(dump_remainder): Move two declarations `down' into the scope
where they are used.
(xlseek): Return the resulting offset.
(file_lines): Rename parameter, file_length, to end_pos.
(pipe_lines): Don't coerce safe_read return value to `int'.
Adapt tests accordingly.
(pipe_bytes) [struct charbuffer] (nbytes): Change type from `int'
to `unsigned int'.
Change type of `total_bytes' from `int' to `size_t',
since the former wouldn't always be wide enough.
Don't coerce safe_read return value to `int',
and adapt tests accordingly.
Now that testing for a read error no longer involves
using `tmp', handle that case *after* freeing `tmp'.
(start_bytes): Clean up.
(tail_bytes): Now that `n_bytes' may be larger than
OFF_T_MAX, test for that condition and, if it's true, don't
use lseek optimizations.
(parse_options): Don't fail just because N_UNITS is larger than
the maximum size of a file -- tail may be applied to an input
stream (e.g., a pipe) with more data than that.
Jim Meyering