Re: wait until the file is done

[Greg Wooledge]

On Fri, Oct 30, 2020 at 06:20:16PM +0100, Mike Jonkmans wrote:
> On Fri, Oct 30, 2020 at 12:52:11PM -0400, Greg Wooledge wrote:
> > 
> > size=$(wc -c < "$file")
> 
> It may be better to use: wc -c "%file"
> As 'wc' can use the file size (via fstat).
> 
> The '<' forces wc to read the file content.
> Which can be significantly slower for large (video) files.

That's not true.

unicorn:~$ strace wc -c < .bashrc
[...]
fstat(0, {st_mode=S_IFREG|0755, st_size=2738, ...}) = 0
lseek(0, 0, SEEK_CUR)                   = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(0x88, 0x3), ...}) = 0
write(1, "2738\n", 52738
)                   = 5
close(0)                                = 0
close(1)                                = 0
close(2)                                = 0
exit_group(0)                           = ?
+++ exited with 0 +++