/* * bin.c * Pastes handling. * * Copyright (c) 2022 * Tom MTT. * * This file is licensed under the 3-Clause BSD License. * You should have received a copy of the 3-Clause BSD License * along with this program. If not, see * . */ #include "bin.h" #include /* for NULL, fclose, fopen, fputs, snprintf, FILE */ #include /* for calloc, free, malloc, rand, realloc */ #include /* for strlen */ #include /* for access, F_OK */ #include "feuille.h" /* for Settings, settings */ /* symbols used to generate IDs */ static char *id_symbols = "abcdefghijklmnopqrstuvwxyz0123456789"; /** * Generate a random ID, until one is available on disk. * min_length: the minimum ID length. Will be increased if a collision occurs. * -> a pointer to the ID. Needs to be freed. */ char *generate_id(int min_length) { int length = min_length; /* allocate a buffer to store the ID */ char *buffer; if ((buffer = calloc(length + 1, sizeof(char))) == NULL) return NULL; /* for each letter, generate a random one */ for (int i = 0; i < length; i++) { if (i > 8 * min_length) return NULL; buffer[i] = id_symbols[rand() % strlen(id_symbols)]; /* collision? */ if (i == length - 1 && paste_exists(buffer)) { /* add one to the ID length and re-allocate the buffer */ length++; void *tmp; if ((tmp = realloc(buffer, (length + 1) * sizeof(char))) == NULL) { free(buffer); return NULL; } buffer = tmp; } } buffer[length] = 0; return buffer; } /** * Check if an ID is already used. * id: the ID in question. * -> 1 if exists, 0 if not. */ int paste_exists(char *id) { return access(id, F_OK) == 0; } /** * Write the paste content to disk. * paste: the string containing the paste. * id: the ID of the paste. * -> 0 if done, -1 if not. */ int write_paste(char *paste, char *id) { /* open the file with write access */ FILE *file; if ((file = fopen(id, "w")) == NULL) return -1; /* write the content to file */ if (fputs(paste, file) == -1) { fclose(file); return -1; } /* close the file (obviously) */ fclose(file); return 0; } /** * Make the full URL for the paste. * id: the ID of the paste. * -> a pointer to the URL. Needs to be freed. */ char *create_url(char *id) { /* calculate the length of the URL */ /* the 3 characters added are the trailing slash, newline and null byte */ int length = strlen(id) + strlen(settings.url) + 3; /* allocate a buffer to store the URL */ char *buffer; if ((buffer = malloc(length * sizeof(char))) == NULL) return NULL; /* set the buffer to the actual URL */ snprintf(buffer, length, "%s/%s\n", settings.url, id); return buffer; }