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#include "bfs.h"
#include "bftw.h"
#include <errno.h>
#include <fcntl.h>
#include <fnmatch.h>
#include <stdio.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <unistd.h>
struct eval_state {
/** Data about the current file. */
struct BFTW *ftwbuf;
/** The parsed command line. */
const cmdline *cl;
/** The bftw() callback return value. */
bftw_action action;
/** A stat() buffer, if necessary. */
struct stat statbuf;
};
/**
* Perform a stat() call if necessary.
*/
static void fill_statbuf(eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
if (ftwbuf->statbuf) {
return;
}
if (fstatat(ftwbuf->at_fd, ftwbuf->at_path, &state->statbuf, AT_SYMLINK_NOFOLLOW) == 0) {
ftwbuf->statbuf = &state->statbuf;
} else {
perror("fstatat()");
}
}
/**
* -true test.
*/
bool eval_true(const expression *expr, eval_state *state) {
return true;
}
/**
* -false test.
*/
bool eval_false(const expression *expr, eval_state *state) {
return false;
}
/**
* -executable, -readable, -writable action.
*/
bool eval_access(const expression *expr, eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
return faccessat(ftwbuf->at_fd, ftwbuf->at_path, expr->idata, AT_SYMLINK_NOFOLLOW) == 0;
}
/**
* -delete action.
*/
bool eval_delete(const expression *expr, eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
int flag = 0;
if (ftwbuf->typeflag == BFTW_DIR) {
flag |= AT_REMOVEDIR;
}
if (unlinkat(ftwbuf->at_fd, ftwbuf->at_path, flag) != 0) {
print_error(state->cl->colors, ftwbuf->path, errno);
state->action = BFTW_STOP;
}
return true;
}
/**
* -prune action.
*/
bool eval_prune(const expression *expr, eval_state *state) {
state->action = BFTW_SKIP_SUBTREE;
return true;
}
/**
* -hidden test.
*/
bool eval_hidden(const expression *expr, eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
return ftwbuf->nameoff > 0 && ftwbuf->path[ftwbuf->nameoff] == '.';
}
/**
* -nohidden action.
*/
bool eval_nohidden(const expression *expr, eval_state *state) {
if (eval_hidden(expr, state)) {
eval_prune(expr, state);
return false;
} else {
return true;
}
}
/**
* -name test.
*/
bool eval_name(const expression *expr, eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
return fnmatch(expr->sdata, ftwbuf->path + ftwbuf->nameoff, 0) == 0;
}
/**
* -path test.
*/
bool eval_path(const expression *expr, eval_state *state) {
struct BFTW *ftwbuf = state->ftwbuf;
return fnmatch(expr->sdata, ftwbuf->path, 0) == 0;
}
/**
* -print action.
*/
bool eval_print(const expression *expr, eval_state *state) {
color_table *colors = state->cl->colors;
if (colors) {
fill_statbuf(state);
}
pretty_print(colors, state->ftwbuf);
return true;
}
/**
* -print0 action.
*/
bool eval_print0(const expression *expr, eval_state *state) {
const char *path = state->ftwbuf->path;
fwrite(path, 1, strlen(path) + 1, stdout);
return true;
}
/**
* -quit action.
*/
bool eval_quit(const expression *expr, eval_state *state) {
state->action = BFTW_STOP;
return true;
}
/**
* -type test.
*/
bool eval_type(const expression *expr, eval_state *state) {
return state->ftwbuf->typeflag == expr->idata;
}
/**
* Evaluate a negation.
*/
bool eval_not(const expression *expr, eval_state *state) {
return !expr->rhs->eval(expr, state);
}
/**
* Evaluate a conjunction.
*/
bool eval_and(const expression *expr, eval_state *state) {
return expr->lhs->eval(expr->lhs, state) && expr->rhs->eval(expr->rhs, state);
}
/**
* Evaluate a disjunction.
*/
bool eval_or(const expression *expr, eval_state *state) {
return expr->lhs->eval(expr->lhs, state) || expr->rhs->eval(expr->rhs, state);
}
/**
* Evaluate the comma operator.
*/
bool eval_comma(const expression *expr, eval_state *state) {
expr->lhs->eval(expr->lhs, state);
return expr->rhs->eval(expr->rhs, state);
}
/**
* Infer the number of open file descriptors we're allowed to have.
*/
static int infer_nopenfd() {
int ret = 4096;
struct rlimit rl;
if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
if (rl.rlim_cur != RLIM_INFINITY) {
ret = rl.rlim_cur;
}
}
// Account for std{in,out,err}
if (ret > 3) {
ret -= 3;
}
return ret;
}
/**
* bftw() callback.
*/
static bftw_action cmdline_callback(struct BFTW *ftwbuf, void *ptr) {
const cmdline *cl = ptr;
if (ftwbuf->typeflag == BFTW_ERROR) {
print_error(cl->colors, ftwbuf->path, ftwbuf->error);
return BFTW_SKIP_SUBTREE;
}
eval_state state = {
.ftwbuf = ftwbuf,
.cl = cl,
.action = BFTW_CONTINUE,
};
if (ftwbuf->depth >= cl->maxdepth) {
state.action = BFTW_SKIP_SUBTREE;
}
// In -depth mode, only handle directories on the BFTW_POST visit
bftw_visit expected_visit = BFTW_PRE;
if ((cl->flags & BFTW_DEPTH)
&& ftwbuf->typeflag == BFTW_DIR
&& ftwbuf->depth < cl->maxdepth) {
expected_visit = BFTW_POST;
}
if (ftwbuf->visit == expected_visit
&& ftwbuf->depth >= cl->mindepth
&& ftwbuf->depth <= cl->maxdepth) {
cl->expr->eval(cl->expr, &state);
}
return state.action;
}
/**
* Evaluate the command line.
*/
int eval_cmdline(cmdline *cl) {
int ret = 0;
int nopenfd = infer_nopenfd();
for (size_t i = 0; i < cl->nroots; ++i) {
if (bftw(cl->roots[i], cmdline_callback, nopenfd, cl->flags, cl) != 0) {
ret = -1;
perror("bftw()");
}
}
return ret;
}
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