Date: Sun, 19 Oct 2014 12:53:40 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 194466] New: Update printf(1) to support %T and %q bashisms [patch] Message-ID: <bug-194466-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194466 Bug ID: 194466 Summary: Update printf(1) to support %T and %q bashisms [patch] Product: Base System Version: 9.3-PRERELEASE Hardware: Any OS: Any Status: Needs Triage Severity: Affects Only Me Priority: Normal Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: mi@ALDAN.algebra.com The printf-implementation built into recent bash offers a very useful feature: %(datefmt)T causes printf to output the date-time string resulting from using datefmt as a format string for strftime(3). The corresponding argument is an integer representing the number of seconds since the epoch. Two special argument values may be used: -1 represents the current time, and -2 represents the time the shell was invoked. The feature makes it easier for script to produce time-stamped logs -- it can now be done without spawning a separate date(1) process for each log-entry. The enclosed patch updates our printf to support it. My patch one-ups bash-implementation by making the format string optional -- if simple %T is used, the "%a %b %d %T %Z %Y" is used by default (same as date(1)). My implementation also provides for future additions of other format-characters, which may need their own (sub)formats. For example, some day we may extend the built-in printf to print information about the process itself and any of the jobs -- using the same format-flexibility as ps(1): printf %(%cpu %mem)P -1 The patch also implements the %q feature of bash's printf to help escape special characters -- for completeness. While here, I also update the oft-used PF-macro to simply use printf(3), instead of the asprintf->fputs->free sequence. This hunk is separate from the new functionality, though, and can be omitted, if the current code is correct. Environment: System: FreeBSD narawntapu 9.3-PRERELEASE Fix: Index: printf.1 =================================================================== --- printf.1 (revision 273142) +++ printf.1 (working copy) @@ -290,6 +290,29 @@ .Cm \e0 Ns Ar num instead of .Cm \e Ns Ar num . +.It Cm q +As for +.Cm s , +but with certain characters (such as braces, blanks, parentheses and the like) +escaped. This makes the result (re)usable as shell argument or input. +.It Cm [(format)]T +Interpret the argument as the number of seconds since Unix epoch and turn +it into a timestamp according to +.Ar format . +If format is omitted, the string "%a %b %d %T %Z %Y" will be used -- this +is, what date(1) does by default. The specified format is passed to strftime(3). +As with +.Nm bash , +two special values for seconds-value are recognized to mean: +.Bl -tag -width Ds +.It -1 +current time. This allows scripts to log messages with timestamps without +executing date(1) for each message. +.It -2 +time, when the current sh-process was started. When using the standalone +.Nm +(rather than the sh-builtin), -2 and -1 are identical. +.El .It Cm \&% Print a `%'; no argument is used. .El @@ -322,6 +345,7 @@ .Xr echo 1 , .Xr sh 1 , .Xr printf 3 +.Xr strftime 3 .Sh STANDARDS The .Nm Index: printf.c =================================================================== --- printf.c (revision 273142) +++ printf.c (working copy) @@ -47,7 +47,12 @@ "$FreeBSD$"; #endif /* not lint */ +#include <sys/time.h> #include <sys/types.h> +#ifdef SHELL +#include <sys/sysctl.h> +#include <sys/user.h> +#endif #include <err.h> #include <errno.h> @@ -67,20 +72,15 @@ #endif #define PF(f, func) do { \ - char *b = NULL; \ if (havewidth) \ if (haveprec) \ - (void)asprintf(&b, f, fieldwidth, precision, func); \ + (void)printf(f, fieldwidth, precision, func); \ else \ - (void)asprintf(&b, f, fieldwidth, func); \ + (void)printf(f, fieldwidth, func); \ else if (haveprec) \ - (void)asprintf(&b, f, precision, func); \ + (void)printf(f, precision, func); \ else \ - (void)asprintf(&b, f, func); \ - if (b) { \ - (void)fputs(b, stdout); \ - free(b); \ - } \ + (void)printf(f, func); \ } while (0) static int asciicode(void); @@ -93,6 +93,9 @@ static const char *getstr(void); static char *mknum(char *, char); +#if defined(SHELL) +static void getstarttime(struct timeval *ptv); +#endif static void usage(void); static char **gargv; @@ -191,7 +194,10 @@ { static const char skip1[] = "#'-+ 0"; static const char skip2[] = "0123456789"; + static const char needescaping[] = "\n\t !\"$&'()*,;<>?[\\]^`{|}"; + char *fmt; + static char *subfmt; int fieldwidth, haveprec, havewidth, mod_ldbl, precision; char convch, nextch; @@ -281,6 +287,25 @@ PF(start, p); break; } + case 'q': { + const char *s, *p; + + s = getstr(); + /* + * #-signs only need escaping, if found at the beginning. + * ~ is only escaped at the beginning or after ':' or '=' + * Other special characters are always escaped: + */ + for (p = s; *p != '\0'; p++) { + if ((*p == '#' && p == s) || + (*p == '~' && + (p == s || p[-1] == ':' || p[-1] == '=')) || + index(needescaping, *p)) { + putchar('\\'); + } + putchar(*p); + } + } case 's': { const char *p; @@ -319,6 +344,98 @@ PF(start, (double)p); break; } + case '(': { + char *end = index(fmt + 1, ')'); + + if (end == NULL) { + warnx("No closing ')' detected"); + return (NULL); + } + + if (subfmt != NULL) { + warnx("Subformat \"%s\" already set", subfmt); + return NULL; + } + if (end == fmt) + break; /* Empty format -- presume default */ + asprintf(&subfmt, "%c%.*s", nextch, + (int)(end - fmt - 1), fmt + 1); + if (subfmt == NULL) { + warnx("%s", strerror(ENOMEM)); + return (NULL); + } + *fmt = nextch; + *end = '%'; + return (end); + } + case 'T': { + char *timebuf = NULL; + size_t buflen, timelen; + const char *timefmt; + intmax_t val; + uintmax_t uval; + struct timeval tv; + + if (subfmt == NULL) + timefmt = "%a %b %d %T %Z %Y"; /* date(1)'s default */ + else + timefmt = subfmt; + if (getnum(&val, &uval, 1) || (tv.tv_sec = val) != val) { + if (subfmt != NULL) { + free(subfmt); + subfmt = NULL; + } + *rval = 1; + return NULL; + } + switch (tv.tv_sec) { + case -2: +#if defined(SHELL) + getstarttime(&tv); + break; + /* Outside of shell, -2 and -1 both mean current time */ +#endif + case -1: + gettimeofday(&tv, NULL); + break; + default: + if (tv.tv_sec < 0) { + warnx("Can not turn %jd into date/time", val); + if (subfmt != NULL) { + free(subfmt); + subfmt = NULL; + } + *rval = 1; + return NULL; + } + } + /* + * No (easy) way to know, how big the buffer needs to be. + * Start small and double as necessary: + */ + buflen = strlen(timefmt) * 4; /* harmless overestimate */ + do { + buflen *= 2; + timebuf = realloc(timebuf, buflen); + if (timebuf == NULL) { + if (subfmt != NULL) { + free(subfmt); + subfmt = NULL; + } + warnx("%s", strerror(ENOMEM)); + return (NULL); + } + timelen = strftime(timebuf, buflen, timefmt, + localtime(&tv.tv_sec)); + } while(timelen == 0); + fputs(timebuf, stdout); + free(timebuf); + if (subfmt != NULL) { + free(subfmt); + subfmt = NULL; + } + break; + } default: warnx("illegal format character %c", convch); return (NULL); @@ -559,7 +676,43 @@ return (ch); } +#ifdef SHELL static void +getstarttime(struct timeval *ptv) +{ + static time_t start; /* We cache this value */ + int mib[4]; + size_t len; + struct kinfo_proc kp; + + ptv->tv_sec = 0; + ptv->tv_usec = 0; /* Not using microseconds at all */ + + if (start != 0) { + ptv->tv_sec = start; + return; + } + + len = 4; + if (sysctlnametomib("kern.proc.pid", mib, &len) != 0) { + warn("Unable to obtain script start-time: %s", + "sysctlnametomib"); + return; + } + mib[3] = getpid(); + len = sizeof(kp); + if (sysctl(mib, 4, &kp, &len, NULL, 0) != 0) { + warn("Unable to obtain script start-time: %s", + "sysctl"); + return; + } + /* XXX Should we check, whether len still equals sizeof(kinfo_proc)? */ + + start = ptv->tv_sec = kp.ki_start.tv_sec; +} +#endif + +static void usage(void) { (void)fprintf(stderr, "usage: printf format [arguments ...]\n"); -- You are receiving this mail because: You are the assignee for the bug.
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