op_file.c

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#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <fnmatch.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <limits.h>

#include "op_file.h"
#include "op_libiberty.h"

int op_file_readable(char const * file)
{
    struct stat st;
    return !stat(file, &st) && S_ISREG(st.st_mode) && !access(file, R_OK);
}


time_t op_get_mtime(char const * file)
{
    struct stat st;

    if (stat(file, &st))
        return 0;

    return st.st_mtime;
}


int create_dir(char const * dir)
{
    if (mkdir(dir, 0755)) {
        /* FIXME: Does not verify existing is a dir */
        if (errno == EEXIST)
            return 0;
        return errno;
    }

    return 0;
}


int create_path(char const * path)
{
    int ret = 0;

    char * str = xstrdup(path);

    char * pos = str[0] == '/' ? str + 1 : str;

    for ( ; (pos = strchr(pos, '/')) != NULL; ++pos) {
        *pos = '\0';
        ret = create_dir(str);
        *pos = '/';
        if (ret)
            break;
    }

    free(str);
    return ret;
}


inline static int is_dot_or_dotdot(char const * name)
{
    return name[0] == '.' &&
        (name[1] == '\0' ||
         (name[1] == '.' && name[2] == '\0'));
}


/* If non-null is returned, the caller is responsible for freeing
 * the memory allocated for the return value. */
static char * make_pathname_from_dirent(char const * basedir,
                      struct dirent * ent,
                      struct stat * st_buf)
{
    int name_len;
    char * name;
    name_len = strlen(basedir) + strlen("/") + strlen(ent->d_name) + 1;
    name = xmalloc(name_len);
    sprintf(name, "%s/%s", basedir, ent->d_name);
    if (stat(name, st_buf) != 0)
    {
        struct stat lstat_buf;
        int err = errno;
        if (lstat(name, &lstat_buf) == 0 &&
                S_ISLNK(lstat_buf.st_mode)) {
            // dangling symlink -- silently ignore
        } else {
            fprintf(stderr, "stat failed for %s (%s)\n",
                            name, strerror(err));
        }
        free(name);
        name = NULL;
    }
    return name;
}


int get_matching_pathnames(void * name_list, get_pathname_callback getpathname,
               char const * base_dir, char const * filter,
               enum recursion_type recursion)
{
/* The algorithm below depends on recursion type (of which there are 3)
 * and whether the current dirent matches the filter.  There are 6 possible
 * different behaviors, which is why we define 6 case below in the switch
 * statement of the algorithm.  Actually, when the recursion type is
 * MATCH_DIR_ONLY_RECURSION, the behavior is the same, whether or not the dir
 * entry matches the filter.  However, the behavior of the recursion types
 * NO_RECURSION and MATCH_ANY_ENTRY_RECURSION do depend on the dir entry
 * filter match, so for simplicity, we perform this match for all recursion
 * types and logically OR the match result with the  value of the passed
 * recursion_type.
 */
#define NO_MATCH 0
#define MATCH 1

    DIR * dir;
    struct dirent * ent;
    struct stat stat_buffer;
    int match;
    char * name = NULL;

    if (!(dir = opendir(base_dir)))
        return -1;
    while ((ent = readdir(dir)) != 0) {
        if (is_dot_or_dotdot(ent->d_name))
            continue;
        if (fnmatch(filter, ent->d_name, 0) == 0)
            match = 1;
        else
            match = 0;

        switch (recursion | match) {
        case NO_RECURSION + NO_MATCH:
        case MATCH_ANY_ENTRY_RECURSION + NO_MATCH:
            // nothing to do but continue the loop
            break;
        case NO_RECURSION + MATCH:
            getpathname(ent->d_name, name_list);
            break;
        case MATCH_ANY_ENTRY_RECURSION + MATCH:
            name = make_pathname_from_dirent(base_dir, ent,
                               &stat_buffer);
            if (name) {
                if (S_ISDIR(stat_buffer.st_mode)) {
                    get_matching_pathnames(
                        name_list, getpathname,
                        name, filter, recursion);
                } else {
                    getpathname(name, name_list);
                }
            }
            free(name);
            break;
        case MATCH_DIR_ONLY_RECURSION + NO_MATCH:
        case MATCH_DIR_ONLY_RECURSION + MATCH:
            name = make_pathname_from_dirent(base_dir, ent,
                               &stat_buffer);
            if (name && S_ISDIR(stat_buffer.st_mode)) {
                /* Check if full directory name contains
                 * match to the filter; if so, add it to
                 * name_list and quit; else, recurse.
                 */
                if (!fnmatch(filter, name, 0)) {
                    getpathname(name, name_list);
                } else {
                    get_matching_pathnames(
                        name_list, getpathname,
                        name, filter, recursion);
                }
            }
            free(name);
            break;
        }
    }
    closedir(dir);

    return 0;
}