Mercurial > hg > toybox
view toys/posix/cat.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 | 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); }