/*      $NetBSD: progress.c,v 1.25 2021/08/17 07:18:43 gson Exp $ */

/*-
 * Copyright (c) 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by John Hawkinson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: progress.c,v 1.25 2021/08/17 07:18:43 gson Exp $");
#endif                          /* not lint */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define GLOBAL                  /* force GLOBAL decls in progressbar.h to be
                                 * declared */
#include "progressbar.h"

static void broken_pipe(int unused);
__dead static void usage(void);

static void
broken_pipe(int unused)
{
        signal(SIGPIPE, SIG_DFL);
        progressmeter(1);
        kill(getpid(), SIGPIPE);
}

static void
usage(void)
{
        fprintf(stderr,
            "usage: %s [-ez] [-b buffersize] [-f file] [-l length]\n"
            "       %*.s [-p prefix] cmd [args...]\n",
            getprogname(), (int) strlen(getprogname()), "");
        exit(EXIT_FAILURE);
}

int
main(int argc, char *argv[])
{
        char *fb_buf;
        char *infile = NULL;
        pid_t pid = 0, gzippid = 0, deadpid;
        int ch, fd, outpipe[2];
        int ws, gzipstat, cmdstat;
        int eflag = 0, lflag = 0, zflag = 0;
        ssize_t nr, nw, off;
        size_t buffersize;
        struct stat statb;
        struct ttysize ts;

        setprogname(argv[0]);

        /* defaults: Read from stdin, 0 filesize (no completion estimate) */
        fd = STDIN_FILENO;
        filesize = 0;
        buffersize = 64 * 1024;
        prefix = NULL;

        while ((ch = getopt(argc, argv, "b:ef:l:p:z")) != -1)
                switch (ch) {
                case 'b':
                        buffersize = (size_t) strsuftoll("buffer size", optarg,
                            0, SSIZE_MAX);
                        break;
                case 'e':
                        eflag++;
                        break;
                case 'f':
                        infile = optarg;
                        break;
                case 'l':
                        lflag++;
                        filesize = strsuftoll("input size", optarg, 0,
                            LLONG_MAX);
                        break;
                case 'p':
                        prefix = optarg;
                        break;
                case 'z':
                        zflag++;
                        break;
                case '?':
                default:
                        usage();
                        /* NOTREACHED */
                }
        argc -= optind;
        argv += optind;

        if (argc < 1)
                usage();

        if (infile && (fd = open(infile, O_RDONLY, 0)) < 0)
                err(1, "%s", infile);

        /* stat() to get the filesize unless overridden, or -z */
        if (!zflag && !lflag && (fstat(fd, &statb) == 0)) {
                if (S_ISFIFO(statb.st_mode)) {
                        /* stat(2) on pipe may return only the
                         * first few bytes with more coming.
                         * Don't trust!
                         */
                } else {
                        filesize = statb.st_size;
                }
        }

        /* gzip -l the file if we have the name and -z is given */
        if (zflag && !lflag && infile != NULL) {
                FILE *gzipsizepipe;
                char buf[256], *cp, *cmd;

                /*
                 * Read second word of last line of gzip -l output. Looks like:
                 * % gzip -l ../etc.tgz 
                 *   compressed uncompressed  ratio uncompressed_name
                 *       119737       696320  82.8% ../etc.tar
                 */

                asprintf(&cmd, "gzip -l %s", infile);
                if ((gzipsizepipe = popen(cmd, "r")) == NULL)
                        err(1, "reading compressed file length");
                for (; fgets(buf, 256, gzipsizepipe) != NULL;)
                    continue;
                strtoimax(buf, &cp, 10);
                filesize = strtoimax(cp, NULL, 10);
                if (pclose(gzipsizepipe) < 0)
                        err(1, "closing compressed file length pipe");
                free(cmd);
        }
        /* Pipe input through gzip -dc if -z is given */
        if (zflag) {
                int gzippipe[2];

                if (pipe(gzippipe) < 0)
                        err(1, "gzip pipe");
                gzippid = fork();
                if (gzippid < 0)
                        err(1, "fork for gzip");

                if (gzippid) {
                        /* parent */
                        dup2(gzippipe[0], fd);
                        close(gzippipe[0]);
                        close(gzippipe[1]);
                } else {
                        dup2(gzippipe[1], STDOUT_FILENO);
                        dup2(fd, STDIN_FILENO);
                        close(gzippipe[0]);
                        close(gzippipe[1]);
                        if (execlp("gzip", "gzip", "-dc", NULL))
                                err(1, "exec()ing gzip");
                }
        }

        /* Initialize progressbar.c's global state */
        bytes = 0;
        progress = 1;
        ttyout = eflag ? stderr : stdout;

        if (ioctl(fileno(ttyout), TIOCGSIZE, &ts) == -1)
                ttywidth = 80;
        else
                ttywidth = ts.ts_cols;

        fb_buf = malloc(buffersize);
        if (fb_buf == NULL)
                err(1, "malloc for buffersize");

        if (pipe(outpipe) < 0)
                err(1, "output pipe");
        pid = fork();
        if (pid < 0)
                err(1, "fork for output pipe");

        if (pid == 0) {
                /* child */
                dup2(outpipe[0], STDIN_FILENO);
                close(outpipe[0]);
                close(outpipe[1]);
                execvp(argv[0], argv);
                err(1, "could not exec %s", argv[0]);
        }
        close(outpipe[0]);

        signal(SIGPIPE, broken_pipe);
        progressmeter(-1);

        while (1) {
                do {
                        nr = read(fd, fb_buf, buffersize);
                } while (nr < 0 && errno == EINTR);
                if (nr < 0) {
                        progressmeter(1);
                        err(1, "reading input");
                }
                if (nr == 0)
                        break;
                for (off = 0; nr; nr -= nw, off += nw, bytes += nw)
                        if ((nw = write(outpipe[1], fb_buf + off,
                            (size_t) nr)) < 0) {
                                if (errno == EINTR) {
                                        nw = 0;
                                        continue;
                                }
                                progressmeter(1);
                                err(1, "writing %u bytes to output pipe",
                                                        (unsigned) nr);
                        }
        }
        close(outpipe[1]);

        gzipstat = 0;
        cmdstat = 0;
        while (pid || gzippid) {
                deadpid = wait(&ws);
                /*
                 * We need to exit with an error if the command (or gzip)
                 * exited abnormally.
                 * Unfortunately we can't generate a true 'exited by signal'
                 * error without sending the signal to ourselves :-(
                 */
                ws = WIFSIGNALED(ws) ? WTERMSIG(ws) : WEXITSTATUS(ws);

                if (deadpid == -1 && errno == EINTR)
                        continue;
                if (deadpid == pid) {
                        pid = 0;
                        cmdstat = ws;
                        continue;
                }
                if (deadpid == gzippid) {
                        gzippid = 0;
                        gzipstat = ws;
                        continue;
                }
                break;
        }

        progressmeter(1);
        signal(SIGPIPE, SIG_DFL);

        free(fb_buf);

        exit(cmdstat ? cmdstat : gzipstat);
}