cosmopolitan/libc/runtime/zipos-normpath.c
Justine Tunney 110559ce6a
Make ZipOS and Qemu work better
This change improves the dirstream library in a lot of respects,
especially for /zip/... files. Also turn off MAP_STACK on Aarch64
because Qemu seems to implement it differently than Linux and it's
probably responsible for a lot of mysterious crashes.
2023-08-15 18:32:50 -07:00

80 lines
3.1 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/runtime/zipos.internal.h"
static size_t __zipos_trimpath(char *s, int *isabs) {
char *p = s, *q = s;
for (; *q; ++q) {
if (*q == '/') {
while (q[1] == '/') ++q;
if (q[1] == '.' && (q[2] == '/' || q[2] == '\0')) {
++q;
} else {
*p++ = '/';
}
} else {
*p++ = *q;
}
}
if (s < p && p[-1] == '.' && p[-2] == '.' && (p - 2 == s || p[-3] == '/')) {
*p++ = '/';
}
*p = '\0';
if (isabs) {
*isabs = *s == '/';
}
return p - s;
}
size_t __zipos_normpath(char *s) {
int isabs;
char *p = s, *q = s;
__zipos_trimpath(s, &isabs);
if (!*s) return 0;
for (; *q != '\0'; ++q) {
if (q[0] == '/' && q[1] == '.' && q[2] == '.' &&
(q[3] == '/' || q[3] == '\0')) {
char *ep = p;
while (s < ep && *--ep != '/') donothing;
if (ep != p &&
(p[-1] != '.' || p[-2] != '.' || (s < p - 3 && p[-3] != '/'))) {
p = ep;
q += 2;
continue;
} else if (ep == s && isabs) {
q += 2;
continue;
}
}
if (q[0] != '/' || p != s || isabs) {
*p++ = *q;
}
}
if (p == s) {
*p++ = isabs ? '/' : '.';
}
if (p == s + 1 && s[0] == '.') {
*p++ = '/';
}
while (p - s > 1 && p[-1] == '/') {
--p;
}
*p = '\0';
return p - s;
}