Mercurial > hg > toybox
view toys/other/factor.c @ 1613:96aa7ec74936 draft
Fix yet another sed bug.
The s/// command would copy the \ of substitutions before deciding what to
do with them (generally overwriting the \ with the new data). When the
substitution was A) at the very end of the new string, B) resolved to nothing,
it could leave a trailing \ that didn't belong there and didn't get overwritten
because the "copy trailing data" part that copies the original string's null
terminator already happened before the \ overwrote it.
The ghostwheel() function restarts regexes after embedded NUL bytes, but
if the string it's passed is _longer_ than the length it's told then it
gets confused (and it means we're off the end of our allocation so segfaults
are likely).
Fix: test for \ first and move the "copy byte" logic into an else case.
author | Rob Landley <rob@landley.net> |
---|---|
date | Mon, 15 Dec 2014 03:34:55 -0600 |
parents | dd336488a69b |
children | 89384d54d49a |
line wrap: on
line source
/* factor.c - Factor integers * * Copyright 2014 Rob Landley <rob@landley.net> * * No standard, but it's in coreutils USE_FACTOR(NEWTOY(factor, 0, TOYFLAG_USR|TOYFLAG_BIN)) config FACTOR bool "factor" default y help usage: factor NUMBER... Factor integers. */ #include "toys.h" static void factor(char *s) { long l, ll; l = strtol(s, &s, 0); if (*s) { error_msg("%s: not integer"); return; } printf("%ld:", l); // Negative numbers have -1 as a factor if (l < 0) { printf(" -1"); l *= -1; } // Deal with 0 and 1 (and 2 since we're here) if (l < 3) { printf(" %ld\n", l); return; } // Special case factors of 2 while (l && !(l&1)) { printf(" 2"); l >>= 1; } // test odd numbers. for (ll=3; ;ll += 2) { long lll = ll*ll; if (lll>l || lll<ll) { if (l>1) printf(" %ld", l); break; } while (!(l%ll)) { printf(" %ld", ll); l /= ll; } } xputc('\n'); } void factor_main(void) { if (toys.optc) { char **ss; for (ss = toys.optargs; *ss; ss++) factor(*ss); } else for (;;) { char *s = 0; size_t len = 0; if (-1 == getline(&s, &len, stdin)) break; factor(s); } }