Mercurial > hg > toybox
view toys/posix/nice.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 | 144d5ba7d410 |
children | cbb1aca81eca |
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/* nice.c - Run a program at a different niceness level. * * Copyright 2010 Rob Landley <rob@landley.net> * * See http://opengroup.org/onlinepubs/9699919799/utilities/nice.html USE_NICE(NEWTOY(nice, "^<1n#", TOYFLAG_USR|TOYFLAG_BIN)) config NICE bool "nice" default y help usage: nice [-n PRIORITY] command [args...] Run a command line at an increased or decreased scheduling priority. Higher numbers make a program yield more CPU time, from -20 (highest priority) to 19 (lowest). By default processes inherit their parent's niceness (usually 0). By default this command adds 10 to the parent's priority. Only root can set a negative niceness level. */ #define FOR_nice #include "toys.h" GLOBALS( long priority; ) void nice_main(void) { if (!toys.optflags) TT.priority = 10; errno = 0; if (nice(TT.priority)==-1 && errno) perror_exit("Can't set priority"); xexec_optargs(0); }