wheres.c - wheres

(133 lines)
   1 #define _GNU_SOURCE
   2 #include <dirent.h>
   3 #include <fnmatch.h>
   4 #include <stdbool.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9 
  10 #include "argparse.h"
  11 
  12 const char *program_name = "wheres";
  13 static const char *USAGE =
  14     "Usage:\n"
  15     "   patterns or paths...: patterns to search for or paths to search for them in\n"
  16     "   --help,-h: print this help message\n"
  17     "   --dir,-d <dir>: search in a given directory\n"
  18     "   --ignorecase,-i: search case-insensitively\n"
  19     "   --type,-t <type>: search for (f)iles, (d)irectories, (l)inks, (p)ipes, (s)ockets, (b)lock "
  20     "devices, (c)haracter devices\n"
  21     "   --nul,-0: print a nul byte instead of a newline after each match\n";
  22 
  23 #ifndef streq
  24 #define streq(str, target) (strcmp(str, target) == 0)
  25 #endif
  26 
  27 static int pat_flags = FNM_PATHNAME;
  28 static const char *type = NULL;
  29 static char print_separator = '\n';
  30 
  31 static inline bool matches_any_pattern(const char *name, int patc, const char *patv[patc]) {
  32     if (patc == 0) return true;
  33     for (int i = 0; i < patc; i++) {
  34         if (fnmatch(patv[i], name, pat_flags) == 0) {
  35             return true;
  36         }
  37     }
  38     return false;
  39 }
  40 
  41 static inline bool is_valid_type(struct dirent *entry) {
  42     if (type == NULL) return true;
  43     switch (entry->d_type) {
  44     case DT_FIFO: return strchr(type, 'p') != NULL;
  45     case DT_CHR: return strchr(type, 'c') != NULL;
  46     case DT_DIR: return strchr(type, 'd') != NULL;
  47     case DT_BLK: return strchr(type, 'b') != NULL;
  48     case DT_REG: return strchr(type, 'f') != NULL;
  49     case DT_LNK: return strchr(type, 'l') != NULL;
  50     case DT_SOCK: return strchr(type, 's') != NULL;
  51     case DT_WHT: return strchr(type, 'w') != NULL;
  52     default: return false;
  53     }
  54 }
  55 
  56 void find(const char *path, int patc, const char *patv[patc]) {
  57     DIR *dir = opendir(path);
  58     if (!dir) return;
  59 
  60     struct dirent *entry;
  61     while ((entry = readdir(dir)) != NULL) {
  62         const char *name = entry->d_name;
  63         if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'))) {
  64             // Skip '.' and '..'
  65             continue;
  66         }
  67 
  68         if (is_valid_type(entry) && matches_any_pattern(name, patc, patv)) {
  69             dprintf(STDOUT_FILENO, "%s/%s%c", path, name, print_separator);
  70         }
  71 
  72         if (entry->d_type == DT_DIR) {
  73             char new_path[PATH_MAX];
  74             snprintf(new_path, sizeof(new_path), "%s/%s", streq(path, "/") ? "" : path, name);
  75             find(new_path, patc, patv);
  76         }
  77     }
  78     closedir(dir);
  79 }
  80 
  81 int main(int argc, char *argv[]) {
  82     program_name = argv[0];
  83     int num_dirs = 0;
  84     // This array is guaranteed to be big enough, since argc >= 1, and each argument
  85     // adds at most one search dir.
  86     const char *dirs[argc] = {};
  87     int num_pats = 0;
  88     const char *pats[argc] = {};
  89     for (int i = 1; i < argc;) {
  90         const char *dir;
  91         const char *new_type;
  92         if (streq(argv[i], "--")) {
  93             break;
  94         } else if ((dir = pop_str_arg(program_name, USAGE, "--dir", 'd', &i, argc, argv))) {
  95             dirs[num_dirs++] = dir;
  96         } else if (pop_bool_arg("--ignorecase", 'i', &i, argc, argv)) {
  97             pat_flags |= FNM_CASEFOLD;
  98         } else if (pop_bool_arg("--help", 'h', &i, argc, argv)) {
  99             printf("%s - find files and directories\n\n%s", program_name, USAGE);
 100             return 0;
 101         } else if ((new_type = pop_str_arg(program_name, USAGE, "--type", 't', &i, argc, argv)) != NULL) {
 102             type = new_type;
 103             continue;
 104         } else if (pop_bool_arg("--nul", '0', &i, argc, argv)) {
 105             print_separator = '\0';
 106         } else if (strchr(argv[i], '/') || streq(argv[i], "..") || streq(argv[i], ".") || streq(argv[i], "~")) {
 107             dirs[num_dirs++] = argv[i];
 108             i += 1;
 109         } else if (argv[i][0] == '-') {
 110             USAGE_ERROR(program_name, USAGE, "Unrecognized argument: %s", argv[i]);
 111         } else {
 112             pats[num_pats++] = argv[i];
 113             i += 1;
 114         }
 115     }
 116 
 117     if (num_dirs == 0) {
 118         dirs[num_dirs++] = ".";
 119     }
 120 
 121     for (int i = 0; i < num_dirs; i++) {
 122         static char real[PATH_MAX];
 123         char *path = realpath(dirs[i], real);
 124         if (!path) {
 125             fprintf(stderr, "Not a valid path: %s", dirs[i]);
 126             exit(1);
 127         }
 128         find(path, num_pats, pats);
 129         if (path != real) free(path);
 130     }
 131 
 132     return 0;
 133 }