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Diffstat (limited to 'examples/loadables/sleep.c')
| -rw-r--r-- | examples/loadables/sleep.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/examples/loadables/sleep.c b/examples/loadables/sleep.c new file mode 100644 index 0000000..204601f --- /dev/null +++ b/examples/loadables/sleep.c @@ -0,0 +1,179 @@ +/* + * sleep -- sleep for fractions of a second + * + * usage: sleep seconds[.fraction] + * + * as an extension, we support the GNU time interval format (2m20s) + */ + +/* + Copyright (C) 1999-2021 Free Software Foundation, Inc. + + This file is part of GNU Bash. + Bash is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + Bash 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "config.h" + +#include "bashtypes.h" + +#if defined (TIME_WITH_SYS_TIME) +# include <sys/time.h> +# include <time.h> +#else +# if defined (HAVE_SYS_TIME_H) +# include <sys/time.h> +# else +# include <time.h> +# endif +#endif + +#if defined (HAVE_UNISTD_H) +#include <unistd.h> +#endif + +#include <stdio.h> +#include "chartypes.h" + +#include "loadables.h" + +#define S_SEC 1 +#define S_MIN (60*S_SEC) +#define S_HOUR (60*S_MIN) +#define S_DAY (24*S_HOUR) + +static int +parse_gnutimefmt (char *string, long *sp, long *up) +{ + int c, r; + char *s, *ep; + long tsec, tusec, accumsec, accumusec, t; + int mult; + + tsec = tusec = 0; + accumsec = accumusec = 0; + mult = 1; + + for (s = string; s && *s; s++) { + r = uconvert(s, &accumsec, &accumusec, &ep); + if (r == 0 && *ep == 0) + return r; + c = *ep; + mult = 1; + switch (c) { + case '\0': + case 's': + mult = S_SEC; + break; + case 'm': + mult = S_MIN; + break; + case 'h': + mult = S_HOUR; + break; + case 'd': + mult = S_DAY; + break; + default: + return 0; + } + + /* multiply the accumulated value by the multiplier */ + t = accumusec * mult; + accumsec = accumsec * mult + (t / 1000000); + accumusec = t % 1000000; + + /* add to running total */ + tsec += accumsec; + tusec += accumusec; + if (tusec >= 1000000) { + tsec++; + tusec -= 1000000; + } + + /* reset and continue */ + accumsec = accumusec = 0; + mult = 1; + if (c == 0) + break; + s = ep; + } + + if (sp) + *sp = tsec; + if (up) + *up = tusec; + + return 1; +} + +int +sleep_builtin (WORD_LIST *list) +{ + long sec, usec; + char *ep; + int r, mul; + time_t t; + + if (list == 0) { + builtin_usage(); + return(EX_USAGE); + } + + /* Skip over `--' */ + if (list->word && ISOPTION (list->word->word, '-')) + list = list->next; + + if (*list->word->word == '-' || list->next) { + builtin_usage (); + return (EX_USAGE); + } + + r = uconvert(list->word->word, &sec, &usec, &ep); + /* + * Maybe postprocess conversion failures here based on EP + * + * A heuristic: if the conversion failed, but the argument appears to + * contain a GNU-like interval specifier (e.g. "1m30s"), try to parse + * it. If we can't, return the right exit code to tell + * execute_builtin to try and execute a disk command instead. + */ + if (r == 0 && (strchr ("dhms", *ep) || strpbrk (list->word->word, "dhms"))) + r = parse_gnutimefmt (list->word->word, &sec, &usec); + + if (r) { + fsleep(sec, usec); + QUIT; + return(EXECUTION_SUCCESS); + } + builtin_error("%s: bad sleep interval", list->word->word); + return (EXECUTION_FAILURE); +} + +static char *sleep_doc[] = { + "Suspend execution for specified period.", + "" + "sleep suspends execution for a minimum of SECONDS[.FRACTION] seconds.", + "As an extension, sleep accepts GNU-style time intervals (e.g., 2m30s).", + (char *)NULL +}; + +struct builtin sleep_struct = { + "sleep", + sleep_builtin, + BUILTIN_ENABLED, + sleep_doc, + "sleep seconds[.fraction]", + 0 +}; |