/* vi: set sw=4 ts=4: */ /* * Adapted from ash applet code * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Copyright (c) 1989, 1991, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au> * was re-ported from NetBSD and debianized. * * Copyright (c) 2010 Denys Vlasenko * Split from ash.c * * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ #include "libbb.h" #include "shell_common.h" #include "builtin_read.h" //TODO: use more efficient setvar() which takes a pointer to malloced "VAR=VAL" //string. hush naturally has it, and ash has setvareq(). //Here we can simply store "VAR=" at buffer start and store read data directly //after "=", then pass buffer to setvar() to consume. const char* FAST_FUNC shell_builtin_read(void FAST_FUNC (*setvar)(const char *name, const char *val), char **argv, const char *ifs, int read_flags, const char *opt_n, const char *opt_p, const char *opt_t, const char *opt_u ) { unsigned end_ms; /* -t TIMEOUT */ int fd; /* -u FD */ int nchars; /* -n NUM */ char **pp; char *buffer; struct termios tty, old_tty; const char *retval; int bufpos; /* need to be able to hold -1 */ int startword; smallint backslash; pp = argv; while (*pp) { if (!is_well_formed_var_name(*pp, '\0')) { /* Mimic bash message */ bb_error_msg("read: '%s': not a valid identifier", *pp); return (const char *)(uintptr_t)1; } pp++; } nchars = 0; /* if != 0, -n is in effect */ if (opt_n) { nchars = bb_strtou(opt_n, NULL, 10); if (nchars < 0 || errno) return "invalid count"; /* note: "-n 0": off (bash 3.2 does this too) */ } end_ms = 0; if (opt_t) { end_ms = bb_strtou(opt_t, NULL, 10); if (errno || end_ms > UINT_MAX / 2048) return "invalid timeout"; end_ms *= 1000; #if 0 /* even bash has no -t N.NNN support */ ts.tv_sec = bb_strtou(opt_t, &p, 10); ts.tv_usec = 0; /* EINVAL means number is ok, but not terminated by NUL */ if (*p == '.' && errno == EINVAL) { char *p2; if (*++p) { int scale; ts.tv_usec = bb_strtou(p, &p2, 10); if (errno) return "invalid timeout"; scale = p2 - p; /* normalize to usec */ if (scale > 6) return "invalid timeout"; while (scale++ < 6) ts.tv_usec *= 10; } } else if (ts.tv_sec < 0 || errno) { return "invalid timeout"; } if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */ return "invalid timeout"; } #endif /* if 0 */ } fd = STDIN_FILENO; if (opt_u) { fd = bb_strtou(opt_u, NULL, 10); if (fd < 0 || errno) return "invalid file descriptor"; } if (opt_p && isatty(fd)) { fputs(opt_p, stderr); fflush_all(); } if (ifs == NULL) ifs = defifs; if (nchars || (read_flags & BUILTIN_READ_SILENT)) { tcgetattr(fd, &tty); old_tty = tty; if (nchars) { tty.c_lflag &= ~ICANON; tty.c_cc[VMIN] = nchars < 256 ? nchars : 255; } if (read_flags & BUILTIN_READ_SILENT) { tty.c_lflag &= ~(ECHO | ECHOK | ECHONL); } /* This forces execution of "restoring" tcgetattr later */ read_flags |= BUILTIN_READ_SILENT; /* if tcgetattr failed, tcsetattr will fail too. * Ignoring, it's harmless. */ tcsetattr(fd, TCSANOW, &tty); } retval = (const char *)(uintptr_t)0; startword = 1; backslash = 0; if (end_ms) /* NB: end_ms stays nonzero: */ end_ms = ((unsigned)monotonic_ms() + end_ms) | 1; buffer = NULL; bufpos = 0; do { char c; if (end_ms) { int timeout; struct pollfd pfd[1]; pfd[0].fd = fd; pfd[0].events = POLLIN; timeout = end_ms - (unsigned)monotonic_ms(); if (timeout <= 0 /* already late? */ || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */ ) { /* timed out! */ retval = (const char *)(uintptr_t)1; goto ret; } } if ((bufpos & 0xff) == 0) buffer = xrealloc(buffer, bufpos + 0x100); if (nonblock_safe_read(fd, &buffer[bufpos], 1) != 1) { retval = (const char *)(uintptr_t)1; break; } c = buffer[bufpos]; if (c == '\0') continue; if (backslash) { backslash = 0; if (c != '\n') goto put; continue; } if (!(read_flags & BUILTIN_READ_RAW) && c == '\\') { backslash = 1; continue; } if (c == '\n') break; /* $IFS splitting. NOT done if we run "read" * without variable names (bash compat). * Thus, "read" and "read REPLY" are not the same. */ if (argv[0]) { /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */ const char *is_ifs = strchr(ifs, c); if (startword && is_ifs) { if (isspace(c)) continue; /* it is a non-space ifs char */ startword--; if (startword == 1) /* first one? */ continue; /* yes, it is not next word yet */ } startword = 0; if (argv[1] != NULL && is_ifs) { buffer[bufpos] = '\0'; bufpos = 0; setvar(*argv, buffer); argv++; /* can we skip one non-space ifs char? (2: yes) */ startword = isspace(c) ? 2 : 1; continue; } } put: bufpos++; } while (--nchars); if (argv[0]) { /* Remove trailing space $IFS chars */ while (--bufpos >= 0 && isspace(buffer[bufpos]) && strchr(ifs, buffer[bufpos]) != NULL) continue; buffer[bufpos + 1] = '\0'; /* Use the remainder as a value for the next variable */ setvar(*argv, buffer); /* Set the rest to "" */ while (*++argv) setvar(*argv, ""); } else { /* Note: no $IFS removal */ buffer[bufpos] = '\0'; setvar("REPLY", buffer); } ret: free(buffer); if (read_flags & BUILTIN_READ_SILENT) tcsetattr(fd, TCSANOW, &old_tty); return retval; }