127 lines
3.3 KiB
C
127 lines
3.3 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#define MAX_PATH_SIZE 512
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#define SEGMENT_LENGTH 2
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#define LAST_SEGMENT_MAX_LENGTH 16
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#define MAX_SEGMENTS_AMOUNT 64
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typedef struct {
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size_t seperator;
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size_t length;
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} Segment;
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/// @returns Amount of segments
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size_t get_path_segments(
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Segment* dest,
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size_t dest_size,
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const char* path,
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size_t path_length)
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{
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size_t dest_i = 0;
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size_t i = 0;
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while (i < path_length) {
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size_t seperator = i;
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i += 1;
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while (path[i] != '\0' && path[i] != '/') {
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i += 1;
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}
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size_t length = i - seperator - 1;
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dest[dest_i] = (Segment) { seperator, length };
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dest_i += 1;
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}
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return dest_i;
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}
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bool in_home_directory(
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const char* path,
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const Segment* segments,
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size_t segments_length,
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const char* username)
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{
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if (segments_length < 2)
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return false;
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if (strncmp(&path[segments[0].seperator + 1], "home", segments[0].length) != 0) {
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return false;
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}
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if (strncmp(&path[segments[1].seperator + 1], username, strlen(username)) != 0) {
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return false;
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}
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return true;
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}
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int main(void)
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{
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char cwd_path[MAX_PATH_SIZE] = "";
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if (getcwd(cwd_path, sizeof(cwd_path)) == NULL) {
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fprintf(stderr, "error: failed to get current working directory: %s\n", strerror(errno));
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exit(1);
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}
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const size_t cwd_path_length = strlen(cwd_path);
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const char* username = getlogin();
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Segment segments[MAX_SEGMENTS_AMOUNT] = { 0 };
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size_t segments_length = get_path_segments(
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segments,
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sizeof(segments) / sizeof(segments[0]),
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cwd_path,
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cwd_path_length);
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bool in_home_dir = in_home_directory(cwd_path, segments, segments_length, username);
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char short_path[MAX_PATH_SIZE] = "";
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size_t segments_i = 0;
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size_t dest_i = 0;
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if (in_home_dir) {
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short_path[dest_i] = '~';
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dest_i += 1;
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segments_i += 2;
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}
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for (; segments_i < segments_length - 1; segments_i += 1) {
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short_path[dest_i] = '/';
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dest_i += 1;
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Segment* segment = &segments[segments_i];
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for (size_t i = 0; i < segment->length && i < SEGMENT_LENGTH; i += 1) {
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short_path[dest_i] = cwd_path[segment->seperator + 1 + i];
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dest_i += 1;
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}
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}
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if (!(segments_length == 2 && in_home_dir)) {
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short_path[dest_i] = '/';
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dest_i += 1;
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Segment* last = &segments[segments_i];
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if (last->length >= LAST_SEGMENT_MAX_LENGTH) {
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for (size_t i = 0; i < 5; i += 1) {
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short_path[dest_i] = cwd_path[last->seperator + 1 + i];
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dest_i += 1;
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}
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for (size_t i = 0; i < 3; i += 1) {
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short_path[dest_i] = '.';
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dest_i += 1;
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}
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for (size_t i = 0; i < 8; i += 1) {
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short_path[dest_i] = cwd_path[last->seperator + 1 + last->length - 8 + i];
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dest_i += 1;
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}
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} else {
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for (size_t i = 0; i < last->length; i += 1) {
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short_path[dest_i] = cwd_path[last->seperator + 1 + i];
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dest_i += 1;
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}
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}
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}
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short_path[dest_i] = '\0';
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fputs(short_path, stdout);
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}
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