WIP: scroll(1) #127
9
Makefile
9
Makefile
@ -32,7 +32,7 @@ RUSTLIBS = --extern getopt=build/o/libgetopt.rlib \
|
||||
CFLAGS += -I$(SYSEXITS)
|
||||
|
||||
.PHONY: all
|
||||
all: dj false fop hru intcmp mm npc rpn scrut str strcmp swab true
|
||||
all: dj false fop hru intcmp mm npc rpn scroll scrut str strcmp swab true
|
||||
|
||||
# keep build/include until bindgen(1) has stdin support
|
||||
# https://github.com/rust-lang/rust-bindgen/issues/2703
|
||||
@ -120,7 +120,12 @@ build/bin/mm: src/mm.rs build rustlibs
|
||||
.PHONY: npc
|
||||
npc: build/bin/npc
|
||||
build/bin/npc: src/npc.c build
|
||||
$(CC) $(CFLAGAS) -o $@ src/npc.c
|
||||
$(CC) $(CFLAGS) -o $@ src/npc.c
|
||||
|
||||
.PHONY: scroll
|
||||
scroll: build/bin/scroll
|
||||
build/bin/scroll: src/scroll.c build
|
||||
$(CC) $(CFLAGS) -o $@ src/scroll.c
|
||||
|
||||
.PHONY: rpn
|
||||
rpn: build/bin/rpn
|
||||
|
||||
52
docs/scroll.1
Normal file
52
docs/scroll.1
Normal file
@ -0,0 +1,52 @@
|
||||
.\" Copyright (c) 2024 DTB <trinity@trinity.moe>
|
||||
.\" Copyright (c) 2024 Emma Tebibyte <emma@tebibyte.media>
|
||||
.\"
|
||||
.\" 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 PG 1 2024-07-31 "Harakit X.X.X"
|
||||
.SH NAME
|
||||
scroll \(en present output
|
||||
.\"
|
||||
.SH SYNOPSIS
|
||||
|
||||
scroll
|
||||
.RB ( -p
|
||||
.RB [ prompt ])
|
||||
.\"
|
||||
.SH DESCRIPTION
|
||||
|
||||
Print standard input to standard output, accepting commands between pages.
|
||||
.\"
|
||||
.SH OPTIONS
|
||||
|
||||
.IP -p
|
||||
Replace the default prompt (\(lq: \(rq) with the option argument.
|
||||
.\"
|
||||
.SH DIAGNOSTICS
|
||||
|
||||
In the event of an error, a debug message will be printed and the program will
|
||||
exit with the appropriate
|
||||
.BR sysexits.h (3)
|
||||
error code.
|
||||
.\"
|
||||
.SH RATIONALE
|
||||
|
||||
Plan 9 from Bell Labs had
|
||||
.BR p (1),
|
||||
a similar \(lqcooked\(rq-mode paginator (as opposed to \(lqraw\(rq mode, which a
|
||||
vast majority of paginators use).
|
||||
.\"
|
||||
.SH AUTHOR
|
||||
|
||||
Written by DTB
|
||||
.MT trinity@trinity.moe
|
||||
.ME .
|
||||
.\"
|
||||
.SH COPYRIGHT
|
||||
|
||||
Copyright \(co 2024 DTB. License AGPLv3+: GNU AGPL version 3 or later
|
||||
<https://gnu.org/licenses/agpl.html>.
|
||||
.\"
|
||||
.SH SEE ALSO
|
||||
.BR more (1p)
|
||||
288
src/scroll.c
Normal file
288
src/scroll.c
Normal file
@ -0,0 +1,288 @@
|
||||
/*
|
||||
* 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 <assert.h> /* assert(3) */
|
||||
#include <errno.h> /* errno */
|
||||
#include <stdbool.h> /* bool */
|
||||
#include <stdio.h> /* fclose(3), feof(3), fgetc(3), fgets(3), fopen(3),
|
||||
* fprintf(3), fputc(3), perror(3), stderr, stdin, stdout,
|
||||
* EOF, FILE, NULL */
|
||||
#include <stdlib.h> /* size_t */
|
||||
#include <string.h> /* strchr(3), strcmp(3) */
|
||||
#include <unistd.h> /* getopt(3) */
|
||||
|
||||
/* Commands start with cmd_. They take an argc and NULL-terminated argv, like
|
||||
* main, and return a status from <sysexits.h>. Return values other than EX_OK
|
||||
* and EX_USAGE cause pg(1) to exit with that value, except EX_UNAVAILABLE,
|
||||
* which causes pg(1) to exit with the status EX_OK. */
|
||||
#include <sysexits.h>
|
||||
|
||||
#define CMDLINE_MAX 99+1 /* Maximum length of command line. */
|
||||
|
||||
static char *whitespace = " \n\r\t\v";
|
||||
|
||||
//static
|
||||
struct Tube {
|
||||
char *name; // command line
|
||||
FILE *in; // process stdin
|
||||
FILE *out; // process stdoout
|
||||
size_t index; // in pipeline
|
||||
};
|
||||
|
||||
static struct {
|
||||
size_t quantity;
|
||||
enum { LINES = 0, BYTES = 1 } type;
|
||||
} default_page_unit = { 22, LINES } /* Plan 9 default */;
|
||||
|
||||
static char *prompt = ": ";
|
||||
static char *program_name = "pg";
|
||||
|
||||
static char *
|
||||
permute_out(char *s, size_t i) {
|
||||
for (
|
||||
;
|
||||
s[i] != '\0';
|
||||
s[i] = s[i + 1], ++i
|
||||
);
|
||||
|
||||
return s;
|
||||
}
|
||||
|
||||
/* strtok(3p), but supports double-quotes and escapes (but only for escaping
|
||||
* quotes). Unmatched quotes in str are considered literal. The behavior of
|
||||
* strtok_quoted when '\'', '"', or '\\' are in sep is undefined. Use of UTF-8
|
||||
* separators with strtok_quoted is undefined. */
|
||||
static char *
|
||||
strtok_quoted(char *str, char *sep) {
|
||||
static char *s;
|
||||
|
||||
if (str != NULL) { s = str; }
|
||||
|
||||
while (strchr(sep, *s) != NULL) { // skip beginning whitespace
|
||||
if(*++s == '\0') { return NULL; } // no remaining except seps
|
||||
}
|
||||
|
||||
{
|
||||
bool in_escape = 0; // previous char was '\\'
|
||||
char quote = '\0'; // quotation mark used, or '\0' if none
|
||||
|
||||
for (int i = 0; s[i] != '\0'; ++i)
|
||||
switch (s[i]) {
|
||||
case '\\':
|
||||
// if literal "\\", permute out a backslash
|
||||
if (in_escape) { (void)permute_out(s, i--); }
|
||||
in_escape = !in_escape;
|
||||
break;
|
||||
case '\'': case '"':
|
||||
if (in_escape) { // \"
|
||||
s[i] = s[i - 1];
|
||||
(void)permute_out(s, i--); // permute out backslash
|
||||
} else if (s[i] == quote) {
|
||||
quote = '\0';
|
||||
(void)permute_out(s, i--); // second quote
|
||||
} else {
|
||||
quote = s[i];
|
||||
if (strchr(&s[i + 1], quote) != NULL) { // has a match
|
||||
(void)permute_out(s, i--); // permute out lquote
|
||||
}
|
||||
}
|
||||
break;
|
||||
case '\0': return s;
|
||||
default:
|
||||
if (!in_escape
|
||||
&& quote == '\0'
|
||||
&& (strchr(sep, s[i]) != NULL || s[i] == '\0')) {
|
||||
char *t; // start of current token
|
||||
|
||||
t = s;
|
||||
s = s[i] != '\0'
|
||||
? &t[i + 1] // store start of next token,
|
||||
: &t[i]; // or the address of the nul if found
|
||||
s[i] = '\0'; // NUL terminate current token
|
||||
|
||||
return t;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return s;
|
||||
}
|
||||
|
||||
/* Page at most l bytes from f without consideration of a buffer (print them to
|
||||
* stdout). */
|
||||
static int
|
||||
pg_b_u(FILE *f, size_t l) {
|
||||
int c;
|
||||
|
||||
while ((c = fgetc(f)) != EOF) {
|
||||
if ((c = fputc(c, stdout)) == EOF || --l == 0) { break; }
|
||||
}
|
||||
|
||||
return c;
|
||||
}
|
||||
|
||||
/* Page at most l lines, which are lengths of characters terminated by nl, from
|
||||
* f without consideration of a buffer (print them to stdout). */
|
||||
static int
|
||||
pg_l_u(FILE *f, size_t l, char nl) {
|
||||
int c;
|
||||
|
||||
while ((c = fgetc(f)) != EOF) {
|
||||
if ((c = fputc(c, stdout)) == EOF || (l -= (c == nl)) == 0) { break; }
|
||||
}
|
||||
|
||||
return c;
|
||||
}
|
||||
|
||||
static int
|
||||
cmd_quit(int argc, char **argv, char **envp) { return EX_UNAVAILABLE; }
|
||||
|
||||
static int
|
||||
cmd_default_page(int argc, char **argv, char **envp) {
|
||||
if (argc > 1) { return EX_USAGE; } // should be impossible
|
||||
else if (default_page_unit.type == BYTES) {
|
||||
return pg_b_u(stdin, default_page_unit.quantity) == EOF
|
||||
? EX_UNAVAILABLE
|
||||
: EX_OK;
|
||||
} else if (default_page_unit.type == LINES) {
|
||||
return pg_l_u(stdin, default_page_unit.quantity, '\n') == EOF
|
||||
? EX_UNAVAILABLE
|
||||
: EX_OK;
|
||||
} else { return EX_SOFTWARE; }
|
||||
}
|
||||
|
||||
static int
|
||||
cmd_page_down_lines(int argc, char **argv, char **envp) {
|
||||
switch (argc) {
|
||||
case 1: return cmd_default_page(argc, argv, envp);
|
||||
case 2: /* not implemented */
|
||||
default:
|
||||
(void)fprintf(stderr, "Usage: %s" /*" (lines)"*/ "\n", argv[0]);
|
||||
return EX_USAGE;
|
||||
}
|
||||
}
|
||||
|
||||
/* A CmdMap must be NULL-terminated. */
|
||||
static struct CmdMap{ char *name; int (*fn)(int, char **, char **); }
|
||||
builtins[] = {
|
||||
/* don't make the user feel trapped */
|
||||
{ ":q", cmd_quit }, { ":q!", cmd_quit },
|
||||
{ "exit", cmd_quit }, { "q", cmd_quit }, { "Q", cmd_quit },
|
||||
{ "quit", cmd_quit }, { "ZZ", cmd_quit },
|
||||
|
||||
{ NULL, NULL }
|
||||
};
|
||||
|
||||
#define ARGV_MAX 10
|
||||
/* Find and execute the command in the command map, given a corresponding
|
||||
* command line. */
|
||||
static int
|
||||
cmdline_exec(struct CmdMap *map, char *cmdline, char **envp) {
|
||||
static int argc;
|
||||
static char *argv[ARGV_MAX];
|
||||
|
||||
if ((argv[(argc = 0)] = strtok_quoted(cmdline, whitespace)) == NULL) {
|
||||
while (cmdline[0] != '\0') { cmdline = &cmdline[1]; }
|
||||
argv[argc] = cmdline;
|
||||
argv[++argc] = NULL;
|
||||
} else {
|
||||
while (
|
||||
(argv[++argc] = strtok_quoted(NULL, whitespace)) != NULL
|
||||
&& argc < ARGV_MAX
|
||||
);
|
||||
}
|
||||
|
||||
for (; map->name != NULL; map = &map[1]) {
|
||||
if(strcmp(map->name, argv[0]) == 0) {
|
||||
return map->fn(argc, argv, envp);
|
||||
}
|
||||
}
|
||||
|
||||
(void)fprintf(stderr, "%s: %s: not found\n", program_name, argv[0]);
|
||||
return EX_USAGE;
|
||||
}
|
||||
|
||||
static int
|
||||
ioerr(char *argv0) {
|
||||
perror(argv0);
|
||||
|
||||
return EX_IOERR;
|
||||
}
|
||||
|
||||
static int
|
||||
usage(char *argv0) {
|
||||
(void)fprintf(stderr, "Usage: %s [-p prompt]\n", argv0);
|
||||
|
||||
return EX_USAGE;
|
||||
}
|
||||
|
||||
int main(int argc, char *argv[]) {
|
||||
unsigned char cmd[CMDLINE_MAX];
|
||||
FILE *t;
|
||||
|
||||
if (argc > 0) {
|
||||
int c;
|
||||
|
||||
program_name = argv[0];
|
||||
|
||||
while ((c = getopt(argc, argv, "p:")) != -1) {
|
||||
switch (c) {
|
||||
case 'p': prompt = optarg; break;
|
||||
default: return usage(program_name);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (argc > optind) { return usage(program_name); }
|
||||
|
||||
|
||||
if ((t = fopen("/dev/tty", "rb")) == NULL) {
|
||||
perror(program_name);
|
||||
|
||||
return EX_OSERR;
|
||||
}
|
||||
|
||||
for (;;) {
|
||||
if (fputs(prompt, stderr) == EOF) { return ioerr(program_name); }
|
||||
|
||||
// if the line...
|
||||
if (fgets((char *)cmd, (sizeof cmd) / (sizeof *cmd), t) != NULL) {
|
||||
if (strchr((char *)cmd, '\n') == NULL) { // was taken incompletely
|
||||
int c;
|
||||
|
||||
while ((c = fgetc(t)) != '\n') { // ...fast-forward stream
|
||||
if (c == EOF) { break; }
|
||||
}
|
||||
}
|
||||
} else { fputc('\n', stdout); } // EOF at start of line; finish prompt
|
||||
|
||||
if (feof(t)) { return EX_OK; }
|
||||
|
||||
{
|
||||
int r;
|
||||
|
||||
switch ((r = cmdline_exec(builtins, (char *)cmd, NULL))){
|
||||
case EX_OK: case EX_USAGE: break;
|
||||
case EX_UNAVAILABLE: return EX_OK;
|
||||
default: return r;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* UNREACHABLE */ assert(0);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user