1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * script implementation for busybox
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4 | *
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5 | * pascal.bellard@ads-lu.com
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6 | *
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7 | * Based on code from util-linux v 2.12r
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8 | * Copyright (c) 1980
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9 | * The Regents of the University of California. All rights reserved.
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10 | *
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11 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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12 | */
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13 | #include "libbb.h"
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14 |
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15 | int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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16 | int script_main(int argc UNUSED_PARAM, char **argv)
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17 | {
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18 | int opt;
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19 | int mode;
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20 | int child_pid;
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21 | int attr_ok; /* NB: 0: ok */
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22 | int winsz_ok;
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23 | int pty;
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24 | char pty_line[GETPTY_BUFSIZE];
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25 | struct termios tt, rtt;
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26 | struct winsize win;
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27 | const char *fname = "typescript";
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28 | const char *shell;
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29 | char shell_opt[] = "-i";
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30 | char *shell_arg = NULL;
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31 | enum {
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32 | OPT_a = (1 << 0),
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33 | OPT_c = (1 << 1),
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34 | OPT_f = (1 << 2),
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35 | OPT_q = (1 << 3),
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36 | OPT_t = (1 << 4),
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37 | };
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38 |
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39 | #if ENABLE_LONG_OPTS
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40 | static const char getopt_longopts[] ALIGN1 =
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41 | "append\0" No_argument "a"
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42 | "command\0" Required_argument "c"
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43 | "flush\0" No_argument "f"
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44 | "quiet\0" No_argument "q"
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45 | IF_SCRIPTREPLAY("timing\0" No_argument "t")
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46 | ;
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47 |
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48 | applet_long_options = getopt_longopts;
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49 | #endif
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50 |
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51 | opt_complementary = "?1"; /* max one arg */
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52 | opt = getopt32(argv, "ac:fq" IF_SCRIPTREPLAY("t") , &shell_arg);
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53 | //argc -= optind;
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54 | argv += optind;
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55 | if (argv[0]) {
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56 | fname = argv[0];
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57 | }
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58 | mode = O_CREAT|O_TRUNC|O_WRONLY;
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59 | if (opt & OPT_a) {
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60 | mode = O_CREAT|O_APPEND|O_WRONLY;
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61 | }
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62 | if (opt & OPT_c) {
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63 | shell_opt[1] = 'c';
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64 | }
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65 | if (!(opt & OPT_q)) {
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66 | printf("Script started, file is %s\n", fname);
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67 | }
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68 | shell = getenv("SHELL");
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69 | if (shell == NULL) {
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70 | shell = DEFAULT_SHELL;
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71 | }
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72 |
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73 | pty = xgetpty(pty_line);
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74 |
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75 | /* get current stdin's tty params */
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76 | attr_ok = tcgetattr(0, &tt);
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77 | winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
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78 |
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79 | rtt = tt;
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80 | cfmakeraw(&rtt);
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81 | rtt.c_lflag &= ~ECHO;
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82 | tcsetattr(0, TCSAFLUSH, &rtt);
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83 |
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84 | /* "script" from util-linux exits when child exits,
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85 | * we wouldn't wait for EOF from slave pty
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86 | * (output may be produced by grandchildren of child) */
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87 | signal(SIGCHLD, record_signo);
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88 |
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89 | /* TODO: SIGWINCH? pass window size changes down to slave? */
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90 |
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91 | child_pid = xvfork();
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92 |
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93 | if (child_pid) {
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94 | /* parent */
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95 | #define buf bb_common_bufsiz1
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96 | struct pollfd pfd[2];
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97 | int outfd, count, loop;
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98 | double oldtime = ENABLE_SCRIPTREPLAY ? time(NULL) : 0;
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99 | smallint fd_count = 2;
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100 |
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101 | outfd = xopen(fname, mode);
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102 | pfd[0].fd = pty;
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103 | pfd[0].events = POLLIN;
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104 | pfd[1].fd = STDIN_FILENO;
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105 | pfd[1].events = POLLIN;
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106 | ndelay_on(pty); /* this descriptor is not shared, can do this */
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107 | /* ndelay_on(STDIN_FILENO); - NO, stdin can be shared! Pity :( */
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108 |
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109 | /* copy stdin to pty master input,
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110 | * copy pty master output to stdout and file */
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111 | /* TODO: don't use full_write's, use proper write buffering */
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112 | while (fd_count && !bb_got_signal) {
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113 | /* not safe_poll! we want SIGCHLD to EINTR poll */
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114 | if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
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115 | /* If child exits too quickly, we may get EIO:
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116 | * for example, try "script -c true" */
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117 | break;
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118 | }
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119 | if (pfd[0].revents) {
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120 | errno = 0;
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121 | count = safe_read(pty, buf, sizeof(buf));
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122 | if (count <= 0 && errno != EAGAIN) {
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123 | /* err/eof from pty: exit */
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124 | goto restore;
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125 | }
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126 | if (count > 0) {
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127 | if (ENABLE_SCRIPTREPLAY && (opt & OPT_t)) {
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128 | struct timeval tv;
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129 | double newtime;
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130 |
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131 | gettimeofday(&tv, NULL);
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132 | newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
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133 | fprintf(stderr, "%f %u\n", newtime - oldtime, count);
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134 | oldtime = newtime;
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135 | }
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136 | full_write(STDOUT_FILENO, buf, count);
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137 | full_write(outfd, buf, count);
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138 | if (opt & OPT_f) {
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139 | fsync(outfd);
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140 | }
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141 | }
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142 | }
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143 | if (pfd[1].revents) {
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144 | count = safe_read(STDIN_FILENO, buf, sizeof(buf));
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145 | if (count <= 0) {
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146 | /* err/eof from stdin: don't read stdin anymore */
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147 | pfd[1].revents = 0;
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148 | fd_count--;
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149 | } else {
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150 | full_write(pty, buf, count);
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151 | }
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152 | }
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153 | }
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154 | /* If loop was exited because SIGCHLD handler set bb_got_signal,
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155 | * there still can be some buffered output. But dont loop forever:
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156 | * we won't pump orphaned grandchildren's output indefinitely.
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157 | * Testcase: running this in script:
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158 | * exec dd if=/dev/zero bs=1M count=1
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159 | * must have "1+0 records in, 1+0 records out" captured too.
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160 | * (util-linux's script doesn't do this. buggy :) */
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161 | loop = 999;
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162 | /* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
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163 | while (--loop && (count = safe_read(pty, buf, sizeof(buf))) > 0) {
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164 | full_write(STDOUT_FILENO, buf, count);
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165 | full_write(outfd, buf, count);
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166 | }
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167 | restore:
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168 | if (attr_ok == 0)
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169 | tcsetattr(0, TCSAFLUSH, &tt);
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170 | if (!(opt & OPT_q))
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171 | printf("Script done, file is %s\n", fname);
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172 | return EXIT_SUCCESS;
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173 | }
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174 |
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175 | /* child: make pty slave to be input, output, error; run shell */
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176 | close(pty); /* close pty master */
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177 | /* open pty slave to fd 0,1,2 */
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178 | close(0);
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179 | xopen(pty_line, O_RDWR); /* uses fd 0 */
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180 | xdup2(0, 1);
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181 | xdup2(0, 2);
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182 | /* copy our original stdin tty's parameters to pty */
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183 | if (attr_ok == 0)
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184 | tcsetattr(0, TCSAFLUSH, &tt);
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185 | if (winsz_ok == 0)
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186 | ioctl(0, TIOCSWINSZ, (char *)&win);
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187 | /* set pty as a controlling tty */
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188 | setsid();
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189 | ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
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190 |
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191 | /* Non-ignored signals revert to SIG_DFL on exec anyway */
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192 | /*signal(SIGCHLD, SIG_DFL);*/
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193 | execl(shell, shell, shell_opt, shell_arg, (char *) NULL);
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194 | bb_simple_perror_msg_and_die(shell);
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195 | }
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