utils-std

split.c (6237B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#include "../lib/fs.h"         // auto_file_copy
#include "../lib/truncation.h" // apply_size_suffix
#include <errno.h>
#include <fcntl.h>    // open
#include <limits.h>   // NAME_MAX
#include <stdio.h>    // fprintf
#include <stdlib.h>   // strtoul
#include <string.h>   // strerror
#include <sys/stat.h> // fstat
#include <unistd.h>   // getopt
const char *argv0 = "split";
const char *name = "x";
size_t name_len = 1;
size_t suffix_len = 2, bytes = 0, lines = 0;
char *name_in = NULL;
static int
base26(int id, char *str)
{
	memcpy(str, name, name_len);
	memset(str + name_len, 'a', suffix_len);
	size_t id_p = name_len + suffix_len;
	do
	{
		str[id_p--] = 'a' + (id % 26);
		id /= 26;
	} while(id > 0 && id_p > name_len);
	if(id_p <= name_len)
	{
		fprintf(stderr, "split: Failed representing %d into suffix of length %zu\n", id, suffix_len);
		return -1;
	}
	return 0;
}
static int
split_bytes(void)
{
	int fd_in = STDIN_FILENO;
	if(name_in != NULL)
	{
		fd_in = open(name_in, O_RDONLY | O_NOCTTY);
		if(fd_in < 0)
		{
			fprintf(stderr, "split: Failed opening '%s' file: %s\n", name_in, strerror(errno));
			return 1;
		}
	}
	struct stat fd_in_stat;
	if(fstat(fd_in, &fd_in_stat) != 0)
	{
		fprintf(stderr, "split: Failed getting status from file '%s': %s", name_in, strerror(errno));
		close(fd_in);
		return 1;
	}
	int err = 0;
	off_t wrote = 0;
	int split_id = 0;
	while(wrote < fd_in_stat.st_size)
	{
		char name_out[NAME_MAX] = "";
		if(base26(split_id++, name_out) < 0) return 1;
		int fd_out = open(name_out, O_WRONLY | O_NOCTTY | O_CREAT, 0644);
		if(fd_out < 0)
		{
			fprintf(stderr, "split: Failed opening '%s' file: %s\n", name_out, strerror(errno));
			err = 1;
			break;
		}
		int ret = auto_file_copy(fd_in, fd_out, bytes, 0);
		if(ret < 0)
		{
			fprintf(stderr,
			        "split: Error while copying from file '%s' to file '%s': %s\n",
			        name_in ? name_in : "<stdin>",
			        name_out,
			        strerror(errno));
			close(fd_out);
			err = 1;
			break;
		}
		wrote += ret;
		if(close(fd_out) < 0)
		{
			fprintf(stderr, "split: Failing closing file '%s': %s\n", name_out, strerror(errno));
			err = 1;
			break;
		}
	}
	if(name_in != NULL) close(fd_in);
	return err;
}
static int
split_lines(void)
{
	FILE *in = stdin;
	if(name_in != NULL)
	{
		in = fopen(name_in, "r");
		if(in == NULL)
		{
			fprintf(stderr, "split: Failed opening '%s' file: %s\n", name_in, strerror(errno));
			return 1;
		}
	}
	int err = 0;
	char *line = NULL;
	size_t line_len = 0;
	int split_id = 0;
	while(true)
	{
		if(feof(in)) break;
		if(ferror(in))
		{
			fprintf(stderr, "split: Failed reading line from file '%s': %s\n", name_in, strerror(errno));
			err = 1;
			break;
		}
		char name_out[NAME_MAX] = "";
		if(base26(split_id++, name_out) < 0)
		{
			err = 1;
			break;
		}
		FILE *out = NULL;
		for(size_t i = 0; i < lines; i++)
		{
			ssize_t nread = getline(&line, &line_len, in);
			if(nread < 0)
			{
				if(errno != 0)
				{
					fprintf(
					    stderr, "split: Failed reading line from file '%s': %s\n", name_in, strerror(errno));
					err = 1;
				}
				break;
			}
			if(out == NULL)
			{
				out = fopen(name_out, "w");
				if(out == NULL)
				{
					fprintf(stderr, "split: Failed opening '%s' file: %s\n", name_out, strerror(errno));
					err = 1;
					break;
				}
			}
			if(fwrite(line, nread, 1, out) < 0)
			{
				fprintf(stderr, "split: Failed writing line to file '%s': %s\n", name_out, strerror(errno));
				err = 1;
				break;
			}
		}
		if(out != NULL)
		{
			if(fclose(out) < 0)
			{
				fprintf(stderr, "split: Failing closing file '%s': %s\n", name_out, strerror(errno));
				err = 1;
				break;
			}
		}
		if(err != 0) break;
	}
	if(line_len > 0) free(line);
	if(name_in != NULL) fclose(in);
	return err;
}
static const char *error_opt_b_l = "split: Options -b and -l are mutually exclusive\n";
int
main(int argc, char *argv[])
{
	int c = -1;
	while((c = getopt(argc, argv, ":a:b:l:")) != -1)
	{
		char *endptr = NULL;
		switch(c)
		{
		case 'a':
			suffix_len = strtoul(optarg, &endptr, 0);
			if(suffix_len == 0)
			{
				fprintf(stderr, "split: Error while parsing '-a %s': %s\n", optarg, strerror(errno));
				return 1;
			}
			if(endptr != NULL && *endptr != '\0')
			{
				fprintf(stderr, "split: Invalid trailing characters in '-a %s': %s\n", optarg, endptr);
				return 1;
			}
			break;
		case 'b':
		{
			if(lines != 0)
			{
				fputs(error_opt_b_l, stderr);
				return 1;
			}
			unsigned long opt_b = strtoul(optarg, &endptr, 0);
			if(opt_b == 0)
			{
				fprintf(stderr, "split: Error while parsing '-b %s': %s\n", optarg, strerror(errno));
				return 1;
			}
			if(endptr != NULL && *endptr != 0)
				if(apply_size_suffix(&opt_b, endptr) != 0) return 1;
			bytes = opt_b;
			lines = 0;
			break;
		}
		case 'l':
			if(bytes != 0)
			{
				fputs(error_opt_b_l, stderr);
				return 1;
			}
			lines = strtoul(optarg, &endptr, 0);
			if(lines == 0)
			{
				fprintf(stderr, "split: Error while parsing '-l %s': %s\n", optarg, strerror(errno));
				return 1;
			}
			if(endptr != NULL && *endptr != '\0')
			{
				fprintf(stderr, "split: Invalid trailing characters in '-l %s': %s\n", optarg, endptr);
				return 1;
			}
			break;
		case ':':
			fprintf(stderr, "split: Option '-%c' requires an operand\n", optopt);
			return 1;
		default:
			fprintf(stderr, "split: Unhandled option '-%c'\n", optopt);
			return 1;
		}
	}
	argc -= optind;
	argv += optind;
	if(lines == 0 && bytes == 0) lines = 1000;
	if(argc > 2 || argc < 0)
	{
		fprintf(stderr, "split: Expected 0, 1, or 2 arguments, got %d\n", argc);
		return 1;
	}
	else if(argc >= 1)
	{
		name_in = argv[0];
		if(argc == 2) name = argv[1];
	}
	name_len = strlen(name);
	if(name_len + suffix_len > NAME_MAX)
	{
		fprintf(stderr,
		        "split: Error: name(%zd bytes) + suffix_length(%zd bytes) > NAME_MAX(%d bytes)\n",
		        name_len,
		        suffix_len,
		        NAME_MAX);
		return 1;
	}
	if(bytes != 0) return split_bytes();
	return split_lines();
}