Mercurial > hg > toybox
view toys/posix/cat.c @ 1531:3ff823086c99 draft
Teach ln -f to leave original target alone if link creation fails.
Suggested by Ashwini Sharma, I wound up implementing it by creating the new
link at a temporary name and renaming it over the old one instead of renaming
the old file out of the way and putting it back if it failed.
(Because "mkdir -p one/one/blah && ln -sf /bin/one one" would otherwise
rename one/one out of the way and only notice it can't delete it way at the
end when recovery's darn awkward, vs create new thing and if rename fails
(including EISDIR) that's the main error path. And yes the temporary name
is in the same directory as the destination so we never rename between mounts.)
link over the old one instead of renaming the old file and renaming it back.
author | Rob Landley <rob@landley.net> |
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date | Wed, 22 Oct 2014 17:11:06 -0500 |
parents | fc1bb49e58a9 |
children | f67b1e9e91b4 |
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/* cat.c - copy inputs to stdout. * * Copyright 2006 Rob Landley <rob@landley.net> * * See http://opengroup.org/onlinepubs/9699919799/utilities/cat.html USE_CAT(NEWTOY(cat, "u", TOYFLAG_BIN)) config CAT bool "cat" default y help usage: cat [-u] [file...] Copy (concatenate) files to stdout. If no files listed, copy from stdin. Filename "-" is a synonym for stdin. -u Copy one byte at a time (slow). */ #include "toys.h" static void do_cat(int fd, char *name) { int len, size=toys.optflags ? 1 : sizeof(toybuf); for (;;) { len = read(fd, toybuf, size); if (len<0) perror_msg("%s",name); if (len<1) break; xwrite(1, toybuf, len); } } void cat_main(void) { loopfiles(toys.optargs, do_cat); }