mm(1): add

This commit is contained in:
dtb 2024-02-17 23:43:22 -07:00
parent abb8fdf935
commit 194b19f94b
Signed by: trinity
GPG Key ID: 31FF85CCB6DC7641
3 changed files with 299 additions and 1 deletions

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@ -17,7 +17,7 @@ CC=cc
RUSTC=rustc RUSTC=rustc
.PHONY: all .PHONY: all
all: dj false fop intcmp rpn scrut str strcmp true all: dj false fop intcmp mm rpn scrut str strcmp true
build: build:
# keep build/include until bindgen(1) has stdin support # keep build/include until bindgen(1) has stdin support
@ -79,6 +79,11 @@ intcmp: build/bin/intcmp
build/bin/intcmp: src/intcmp.c build build/bin/intcmp: src/intcmp.c build
$(CC) $(CFLAGS) -o $@ src/intcmp.c $(CC) $(CFLAGS) -o $@ src/intcmp.c
.PHONY: mm
mm: build/bin/mm
build/bin/mm: src/mm.c build
$(CC) $(CFLAGS) -o $@ src/mm.c
.PHONY: rpn .PHONY: rpn
rpn: build/bin/rpn rpn: build/bin/rpn
build/bin/rpn: src/rpn.rs build build/o/libsysexits.rlib build/bin/rpn: src/rpn.rs build build/o/libsysexits.rlib

76
docs/mm.1 Normal file
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@ -0,0 +1,76 @@
.\" Copyright (c) 2024 DTB <trinity@trinity.moe>
.\"
.\" This work is licensed under CC BY-SA 4.0. To see a copy of this license,
.\" visit <http://creativecommons.org/licenses/by-sa/4.0/>.
.TH mm 1
.SH NAME
mm \(en middleman
.SH SYNOPSIS
mm
.RB ( -aenu )
.RB ( -i
.RB [ input ])
.RB ( -o
.RB [ output ])
.SH DESCRIPTION
Mm catenates input files and writes them to the start of each output file.
.SH OPTIONS
Mm, upon receiving the
.B -a
option, will open subsequent outputs for appending rather than updating.
.PP
The
.B -i
option opens a path as an input. Without any inputs specified mm will use
standard input. Standard input itself can be specified by giving the path '-'.
.PP
The
.B -o
option opens a path as an output. Without any outputs specified mm will use
standard output. Standard output itself can be specified by giving the
path '-'. Standard error itself can be specified with the
.B -e
option.
.PP
The
.B -u
option ensures neither input or output will be buffered.
.PP
The
.B -n
option tells mm to ignore SIGINT signals.
.SH DIAGNOSTICS
If an output can no longer be written mm prints a diagnostic message, ceases
writing to that particular output, and if there are more outputs specified,
continues, eventually exiting unsuccessfully.
.PP
On error mm prints a diagnostic message and exits with the appropriate
sysexits.h(3) status.
.SH BUGS
Mm does not truncate existing files, which may lead to unexpected results.
.SH RATIONALE
Mm was modeled after the cat and tee utilities specified in POSIX.
.SH COPYRIGHT
Copyright (C) 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
<https://gnu.org/licenses/agpl.html>.
.SH SEE ALSO
cat(1p), dd(1), dj(1), tee(1p)

217
src/mm.c Normal file
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@ -0,0 +1,217 @@
/*
* 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_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;
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 = 0;
/* 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 = 1;
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[i].s == 0)
terminate;
}
terminate;
}