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Diffstat (limited to '')
| -rw-r--r-- | src/shlex.cc | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/src/shlex.cc b/src/shlex.cc new file mode 100644 index 0000000..8da44bb --- /dev/null +++ b/src/shlex.cc @@ -0,0 +1,218 @@ +/** + * Copyright (c) 2015, Timothy Stack + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of Timothy Stack nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * @file shlex.cc + */ + +#ifdef __CYGWIN__ +# include <alloca.h> +#endif + +#include "config.h" +#include "shlex.hh" + +bool +shlex::tokenize(string_fragment& cap_out, shlex_token_t& token_out) +{ + while (this->s_index < this->s_len) { + switch (this->s_str[this->s_index]) { + case '\\': + cap_out.sf_begin = this->s_index; + if (this->s_index + 1 < this->s_len) { + token_out = shlex_token_t::ST_ESCAPE; + this->s_index += 2; + cap_out.sf_end = this->s_index; + } else { + this->s_index += 1; + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_ERROR; + } + return true; + case '\"': + if (!this->s_ignore_quotes) { + switch (this->s_state) { + case state_t::STATE_NORMAL: + cap_out.sf_begin = this->s_index; + this->s_index += 1; + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_DOUBLE_QUOTE_START; + this->s_state = state_t::STATE_IN_DOUBLE_QUOTE; + return true; + case state_t::STATE_IN_DOUBLE_QUOTE: + cap_out.sf_begin = this->s_index; + this->s_index += 1; + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_DOUBLE_QUOTE_END; + this->s_state = state_t::STATE_NORMAL; + return true; + default: + break; + } + } + break; + case '\'': + if (!this->s_ignore_quotes) { + switch (this->s_state) { + case state_t::STATE_NORMAL: + cap_out.sf_begin = this->s_index; + this->s_index += 1; + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_SINGLE_QUOTE_START; + this->s_state = state_t::STATE_IN_SINGLE_QUOTE; + return true; + case state_t::STATE_IN_SINGLE_QUOTE: + cap_out.sf_begin = this->s_index; + this->s_index += 1; + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_SINGLE_QUOTE_END; + this->s_state = state_t::STATE_NORMAL; + return true; + default: + break; + } + } + break; + case '$': + switch (this->s_state) { + case state_t::STATE_NORMAL: + case state_t::STATE_IN_DOUBLE_QUOTE: + this->scan_variable_ref(cap_out, token_out); + return true; + default: + break; + } + break; + case '~': + switch (this->s_state) { + case state_t::STATE_NORMAL: + cap_out.sf_begin = this->s_index; + this->s_index += 1; + while (this->s_index < this->s_len + && (isalnum(this->s_str[this->s_index]) + || this->s_str[this->s_index] == '_' + || this->s_str[this->s_index] == '-')) + { + this->s_index += 1; + } + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_TILDE; + return true; + default: + break; + } + break; + case ' ': + case '\t': + switch (this->s_state) { + case state_t::STATE_NORMAL: + cap_out.sf_begin = this->s_index; + while (isspace(this->s_str[this->s_index])) { + this->s_index += 1; + } + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_WHITESPACE; + return true; + default: + break; + } + break; + default: + break; + } + + this->s_index += 1; + } + + return false; +} + +void +shlex::scan_variable_ref(string_fragment& cap_out, shlex_token_t& token_out) +{ + cap_out.sf_begin = this->s_index; + this->s_index += 1; + if (this->s_index >= this->s_len) { + cap_out.sf_end = this->s_index; + token_out = shlex_token_t::ST_ERROR; + return; + } + + if (this->s_str[this->s_index] == '{') { + token_out = shlex_token_t::ST_QUOTED_VARIABLE_REF; + this->s_index += 1; + } else { + token_out = shlex_token_t::ST_VARIABLE_REF; + } + + while (this->s_index < this->s_len) { + if (token_out == shlex_token_t::ST_VARIABLE_REF) { + if (isalnum(this->s_str[this->s_index]) + || this->s_str[this->s_index] == '#' + || this->s_str[this->s_index] == '_') + { + this->s_index += 1; + } else { + break; + } + } else { + if (this->s_str[this->s_index] == '}') { + this->s_index += 1; + break; + } + this->s_index += 1; + } + } + + cap_out.sf_end = this->s_index; + if (token_out == shlex_token_t::ST_QUOTED_VARIABLE_REF + && this->s_str[this->s_index - 1] != '}') + { + cap_out.sf_begin += 1; + cap_out.sf_end = cap_out.sf_begin + 1; + token_out = shlex_token_t::ST_ERROR; + } +} + +void +shlex::resolve_home_dir(std::string& result, string_fragment cap) const +{ + if (cap.length() == 1) { + result.append(getenv_opt("HOME").value_or("~")); + } else { + auto username = (char*) alloca(cap.length()); + + memcpy(username, &this->s_str[cap.sf_begin + 1], cap.length() - 1); + username[cap.length() - 1] = '\0'; + auto pw = getpwnam(username); + if (pw != nullptr) { + result.append(pw->pw_dir); + } else { + result.append(&this->s_str[cap.sf_begin], cap.length()); + } + } +} |