bonsix/src/mm.c

225 lines
6.6 KiB
C

/*
* Copyright (c) 2024 DTB <trinity@trinity.moe>
* SPDX-License-Identifier: AGPL-3.0-or-later
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU Affero General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
* details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see https://www.gnu.org/licenses/.
*/
#include <errno.h> /* errno */
#include <signal.h> /* signal(2), SIG_ERR, SIG_IGN, SIGINT */
#include <stdio.h> /* fclose(3), fopen(3), fprintf(3), getc(3), putc(3),
* setvbuf(3), size_t, _IONBF, NULL */
#include <stdlib.h> /* free(3), realloc(3) */
#include <string.h> /* strcmp(3), strerror(3) */
#include <unistd.h> /* getopt(3) */
#if !defined EX_IOERR || !defined EX_OK || !defined EX_OSERR \
|| !defined EX_USAGE
# include <sysexits.h>
#endif
extern int errno;
/* This structure is how open files are tracked. */
struct Files{
size_t a; /* allocation */
size_t s; /* used size */
char *mode; /* file opening mode */
char **names; /* file names */
FILE **files; /* file pointers */
};
/* How much to grow the allocation when it's saturated. */
#ifndef ALLOC_INCREMENT
# define ALLOC_INCREMENT 1
#endif
/* How much to grow the allocation at program start. */
#ifndef ALLOC_INITIAL
# define ALLOC_INITIAL 10
#endif
/* pre-allocated strings */
static char *program_name = "<no argv[0]>";
static char *stdin_name = "<stdin>";
static char *stdout_name = "<stdout>";
static char *stderr_name = "<stderr>";
static char *(fmode[]) = { (char []){"rb"}, (char []){"rb+"} };
static char *wharsh = "wb";
/* Adds the open FILE pointer for the file at the path s to the files struct,
* returning the FILE if successful and NULL if not, allocating more memory in
* the files buffers as needed. */
static FILE *
Files_append(struct Files *files, FILE *file, char *name){
if(file == NULL || (files->s == files->a
&& ((files->files = realloc(files->files,
(files->a += (files->a == 0)
? ALLOC_INITIAL
: ALLOC_INCREMENT)
* sizeof *(files->files))) == NULL
|| (files->names = realloc(files->names,
files->a * sizeof *(files->names))) == NULL)))
return NULL;
files->names[files->s] = name;
return files->files[files->s++] = file;
}
/* Opens the file at the path p and puts it in the files struct, returning NULL
* if either the opening or the placement of the open FILE pointer fail. */
#define Files_open(files, p) \
Files_append((files), fopen((p), (files)->mode), (p))
/* Prints a diagnostic message based on errno and returns an exit status
* appropriate for an OS error. */
static int
oserr(char *s, char *r){
fprintf(stderr, "%s: %s: %s\n", s, r, strerror(errno));
return EX_OSERR;
}
/* Hijacks i and j from main and destructs the files[2] struct used by main by
* closing its files and freeing its files and names arrays, returning retval
* from main. */
#define terminate \
for(i = 0; i < 2; ++i){ \
for(j = 0; j < files[i].s; ++j) \
if(files[i].files[j] != stdin \
&& files[i].files[j] != stdout \
&& files[i].files[j] != stderr) \
fclose(files[i].files[j]); \
free(files[i].files); \
free(files[i].names); \
} \
return retval
int main(int argc, char *argv[]){
int c;
struct Files files[2]; /* {read, write} */
size_t i;
size_t j;
size_t k; /* loop index but also unbuffer status */
int retval;
/* Initializes the files structs with their default values, standard
* input and standard output. If an input or an output is specified
* these initial values will be overwritten, so to, say, use mm(1)
* equivalently to tee(1p), -o - will need to be specified before
* additional files to ensure standard output is still written. */
for(i = 0; i < 2; ++i){
files[i].a = 0;
files[i].s = 0;
files[i].mode = fmode[i];
files[i].files = NULL;
files[i].names = NULL;
Files_append(&files[i], i == 0 ? stdin : stdout,
i == 0 ? stdin_name : stdout_name);
files[i].s = 0;
}
k = 0;
if(argc > 0)
program_name = argv[0];
if(argc > 1)
while((c = getopt(argc, argv, "aehi:no:u")) != -1)
switch(c){
case 'a': /* "rb+" -> "ab" */
files[1].mode[0] = 'a';
files[1].mode[2] = '\0';
break;
case 'e':
if(Files_append(&files[1], stderr, stderr_name) != NULL)
break;
retval = oserr(argv[0], "-e");
terminate;
case 'i':
if((strcmp(optarg, "-") == 0 && Files_append(&files[0],
stdin, stdin_name) != NULL)
|| Files_open(&files[0], optarg) != NULL)
break;
retval = oserr(argv[0], optarg);
terminate;
case 'o':
if((strcmp(optarg, "-") == 0 && Files_append(&files[1],
stdout, stdout_name) != NULL)
|| Files_open(&files[1], optarg) != NULL)
break;
/* does not exist, so try to create it */
if(errno == ENOENT){
files[1].mode = wharsh;
if(Files_open(&files[1], optarg) != NULL){
files[1].mode = fmode[1];
break;
}
}
retval = oserr(argv[0], optarg);
terminate;
case 'n':
if(signal(SIGINT, SIG_IGN) != SIG_ERR)
break;
retval = oserr(argv[0], "-n");
terminate;
case 'u':
k = 1;
break;
default:
fprintf(stderr, "Usage: %s (-aenu) (-i [input])..."
" (-o [output])...\n", argv[0]);
retval = EX_USAGE;
terminate;
}
files[0].s += files[0].s == 0;
files[1].s += files[1].s == 0;
/* Unbuffer files. */
if(k){
for(i = 0;
i < files[0].s;
setvbuf(files[0].files[i++], NULL, _IONBF, 0));
for(i = 0;
i < files[1].s;
setvbuf(files[1].files[i++], NULL, _IONBF, 0));
}
retval = EX_OK;
/* Actual program loop. */
for(i = 0; i < files[0].s; ++i) /* iterate ins */
while((c = getc(files[0].files[i])) != EOF) /* iterate chars */
for(j = 0; j < files[1].s; ++j) /* iterate outs */
if(putc(c, files[1].files[j]) == EOF){
/* notebook's full */
retval = EX_IOERR;
fprintf(stderr, "%s: %s: %s\n",
program_name, files[1].names[j], strerror(errno));
if(fclose(files[1].files[j]) == EOF)
fprintf(stderr, "%s: %s: %s\n",
program_name, files[1].names[j], strerror(errno));
/* massage out the tense muscle */
for(k = j--; k < files[1].s - 1; ++k){
files[1].files[k] = files[1].files[k+1];
files[1].names[k] = files[1].names[k+1];
}
if(--files[1].s == 0)
terminate;
}
terminate;
}