cosmopolitan/libc/runtime/getdosargv.c

113 lines
4.9 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/bits/bits.h"
#include "libc/bits/pushpop.h"
#include "libc/bits/safemacros.h"
#include "libc/runtime/internal.h"
#include "libc/str/appendchar.h"
#include "libc/str/str.h"
#include "libc/str/tpenc.h"
#include "libc/str/utf16.h"
/* TODO(jart): Make early-stage data structures happen. */
#undef isspace
#undef iswspace
#define isspace(c) ((c) == ' ' || (c) == '\t' || (c) == '\n' || (c) == '\r')
#define iswspace(c) isspace(c)
struct DosArgv {
const char16_t *s;
char *p;
char *pe;
wint_t wc;
};
static textwindows void AppendDosArgv(struct DosArgv *st, wint_t wc) {
AppendChar(&st->p, st->pe, wc);
}
/**
* Tokenizes and transcodes Windows NT CLI args, thus avoiding
* CommandLineToArgv() schlepping in forty megs of dependencies.
*
* @param s is the command line string provided by the executive
* @param buf is where we'll store double-NUL-terminated decoded args
* @param size is how many bytes are available in buf
* @param argv is where we'll store the decoded arg pointer array, which
* is guaranteed to be NULL-terminated if max>0
* @param max specifies the item capacity of argv, or 0 to do scanning
* @return number of args written, excluding the NULL-terminator; or,
* if the output buffer wasn't passed, or was too short, then the
* number of args that *would* have been written is returned; and
* there are currently no failure conditions that would have this
* return -1 since it doesn't do system calls
* @see test/libc/dosarg_test.c
* @see libc/runtime/ntspawn.c
* @note kudos to Simon Tatham for figuring out quoting behavior
*/
textwindows int GetDosArgv(const char16_t *cmdline, char *buf, size_t size,
char **argv, size_t max) {
bool inquote;
size_t i, argc, slashes, quotes;
struct DosArgv st;
st.s = cmdline;
st.p = buf;
st.pe = buf + size;
argc = 0;
st.wc = DecodeNtsUtf16(&st.s);
while (st.wc) {
while (st.wc && iswspace(st.wc)) st.wc = DecodeNtsUtf16(&st.s);
if (!st.wc) break;
if (++argc < max) {
argv[argc - 1] = st.p < st.pe ? st.p : NULL;
}
inquote = false;
while (st.wc) {
if (!inquote && isspace(st.wc)) break;
if (st.wc == '"' || st.wc == '\\') {
slashes = 0;
quotes = 0;
while (st.wc == '\\') st.wc = DecodeNtsUtf16(&st.s), slashes++;
while (st.wc == '"') st.wc = DecodeNtsUtf16(&st.s), quotes++;
if (!quotes) {
while (slashes--) AppendDosArgv(&st, '\\');
} else {
while (slashes >= 2) AppendDosArgv(&st, '\\'), slashes -= 2;
if (slashes) AppendDosArgv(&st, '"'), quotes--;
if (quotes > 0) {
if (!inquote) quotes--;
for (i = 3; i <= quotes + 1; i += 3) AppendDosArgv(&st, '"');
inquote = (quotes % 3 == 0);
}
}
} else {
AppendDosArgv(&st, st.wc);
st.wc = DecodeNtsUtf16(&st.s);
}
}
AppendDosArgv(&st, '\0');
}
AppendDosArgv(&st, '\0');
if (size) buf[min(st.p - buf, size - 1)] = '\0';
if (max) argv[min(argc, max - 1)] = NULL;
return argc;
}