diff options
Diffstat (limited to 'shell/ash.c')
| -rw-r--r-- | shell/ash.c | 122 |
1 files changed, 67 insertions, 55 deletions
diff --git a/shell/ash.c b/shell/ash.c index d9ce202..2b6133d 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -11672,10 +11672,18 @@ typedef enum __rlimit_resource rlim_t; #endif /* - * The read builtin. The -e option causes backslashes to escape the - * following character. - * + * The read builtin. Options: + * -r Do not interpret '\' specially + * -s Turn off echo (tty only) + * -n NCHARS Read NCHARS max + * -p PROMPT Display PROMPT on stderr (if input is from tty) + * -t SECONDS Timeout after SECONDS (tty or pipe only) + * -u FD Read from given FD instead of fd 0 * This uses unbuffered input, which may be avoidable in some cases. + * TODO: bash also has: + * -a ARRAY Read into array[0],[1],etc + * -d DELIM End on DELIM char, not newline + * -e Use line editing (tty only) */ static int readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) @@ -11690,31 +11698,23 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) int startword; int status; int i; + int fd = 0; #if ENABLE_ASH_READ_NCHARS - int n_flag = 0; - int nchars = 0; + int nchars = 0; /* if != 0, -n is in effect */ int silent = 0; struct termios tty, old_tty; #endif #if ENABLE_ASH_READ_TIMEOUT - fd_set set; - struct timeval ts; - - ts.tv_sec = ts.tv_usec = 0; + unsigned end_ms = 0; + unsigned timeout = 0; #endif rflag = 0; prompt = NULL; -#if ENABLE_ASH_READ_NCHARS && ENABLE_ASH_READ_TIMEOUT - while ((i = nextopt("p:rt:n:s")) != '\0') -#elif ENABLE_ASH_READ_NCHARS - while ((i = nextopt("p:rn:s")) != '\0') -#elif ENABLE_ASH_READ_TIMEOUT - while ((i = nextopt("p:rt:")) != '\0') -#else - while ((i = nextopt("p:r")) != '\0') -#endif - { + while ((i = nextopt("p:u:r" + USE_ASH_READ_TIMEOUT("t:") + USE_ASH_READ_NCHARS("n:s") + )) != '\0') { switch (i) { case 'p': prompt = optionarg; @@ -11724,7 +11724,7 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) nchars = bb_strtou(optionarg, NULL, 10); if (nchars < 0 || errno) ash_msg_and_raise_error("invalid count"); - n_flag = nchars; /* just a flag "nchars is nonzero" */ + /* nchars == 0: off (bash 3.2 does this too) */ break; case 's': silent = 1; @@ -11732,6 +11732,11 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) #endif #if ENABLE_ASH_READ_TIMEOUT case 't': + timeout = bb_strtou(optionarg, NULL, 10); + if (errno || timeout > UINT_MAX / 2048) + ash_msg_and_raise_error("invalid timeout"); + timeout *= 1000; +#if 0 /* even bash have no -t N.NNN support */ ts.tv_sec = bb_strtou(optionarg, &p, 10); ts.tv_usec = 0; /* EINVAL means number is ok, but not terminated by NUL */ @@ -11755,16 +11760,22 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */ ash_msg_and_raise_error("invalid timeout"); } +#endif /* if 0 */ break; #endif case 'r': rflag = 1; break; + case 'u': + fd = bb_strtou(optionarg, NULL, 10); + if (fd < 0 || errno) + ash_msg_and_raise_error("invalid file descriptor"); + break; default: break; } } - if (prompt && isatty(0)) { + if (prompt && isatty(fd)) { out2str(prompt); } ap = argptr; @@ -11774,46 +11785,48 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) if (ifs == NULL) ifs = defifs; #if ENABLE_ASH_READ_NCHARS - if (n_flag || silent) { - if (tcgetattr(0, &tty) != 0) { - /* Not a tty */ - n_flag = 0; - silent = 0; - } else { - old_tty = tty; - if (n_flag) { - tty.c_lflag &= ~ICANON; - tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; - } - if (silent) { - tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); - } - tcsetattr(0, TCSANOW, &tty); + tcgetattr(fd, &tty); + old_tty = tty; + if (nchars || silent) { + if (nchars) { + tty.c_lflag &= ~ICANON; + tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; } - } -#endif -#if ENABLE_ASH_READ_TIMEOUT - if (ts.tv_sec || ts.tv_usec) { - FD_ZERO(&set); - FD_SET(0, &set); - - /* poll-based wait produces bigger code, using select */ - i = select(1, &set, NULL, NULL, &ts); - if (!i) { /* timed out! */ -#if ENABLE_ASH_READ_NCHARS - if (n_flag) - tcsetattr(0, TCSANOW, &old_tty); -#endif - return 1; + if (silent) { + tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); } + /* if tcgetattr failed, tcsetattr will fail too. + * Ignoring, it's harmless. */ + tcsetattr(fd, TCSANOW, &tty); } #endif + status = 0; startword = 1; backslash = 0; +#if ENABLE_ASH_READ_TIMEOUT + if (timeout) /* NB: ensuring end_ms is nonzero */ + end_ms = ((unsigned)(monotonic_us() / 1000) + timeout) | 1; +#endif STARTSTACKSTR(p); do { - if (nonblock_safe_read(0, &c, 1) != 1) { +#if ENABLE_ASH_READ_TIMEOUT + if (end_ms) { + struct pollfd pfd[1]; + pfd[0].fd = fd; + pfd[0].events = POLLIN; + timeout = end_ms - (unsigned)(monotonic_us() / 1000); + if ((int)timeout <= 0 /* already late? */ + || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */ + ) { /* timed out! */ +#if ENABLE_ASH_READ_NCHARS + tcsetattr(fd, TCSANOW, &old_tty); +#endif + return 1; + } + } +#endif + if (nonblock_safe_read(fd, &c, 1) != 1) { status = 1; break; } @@ -11848,14 +11861,13 @@ readcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) } /* end of do {} while: */ #if ENABLE_ASH_READ_NCHARS - while (!n_flag || --nchars); + while (--nchars); #else while (1); #endif #if ENABLE_ASH_READ_NCHARS - if (n_flag || silent) - tcsetattr(0, TCSANOW, &old_tty); + tcsetattr(fd, TCSANOW, &old_tty); #endif STACKSTRNUL(p); |