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Diffstat (limited to 'newlib/libc/time/strftime.c')
| -rw-r--r-- | newlib/libc/time/strftime.c | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/newlib/libc/time/strftime.c b/newlib/libc/time/strftime.c new file mode 100644 index 00000000000..1e6154f127f --- /dev/null +++ b/newlib/libc/time/strftime.c @@ -0,0 +1,444 @@ +/* + * strftime.c + * Original Author: G. Haley + * + * Places characters into the array pointed to by s as controlled by the string + * pointed to by format. If the total number of resulting characters including + * the terminating null character is not more than maxsize, returns the number + * of characters placed into the array pointed to by s (not including the + * terminating null character); otherwise zero is returned and the contents of + * the array indeterminate. + */ + +/* +FUNCTION +<<strftime>>---flexible calendar time formatter + +INDEX + strftime + +ANSI_SYNOPSIS + #include <time.h> + size_t strftime(char *<[s]>, size_t <[maxsize]>, + const char *<[format]>, const struct tm *<[timp]>); + +TRAD_SYNOPSIS + #include <time.h> + size_t strftime(<[s]>, <[maxsize]>, <[format]>, <[timp]>) + char *<[s]>; + size_t <[maxsize]>; + char *<[format]>; + struct tm *<[timp]>; + +DESCRIPTION +<<strftime>> converts a <<struct tm>> representation of the time (at +<[timp]>) into a string, starting at <[s]> and occupying no more than +<[maxsize]> characters. + +You control the format of the output using the string at <[format]>. +<<*<[format]>>> can contain two kinds of specifications: text to be +copied literally into the formatted string, and time conversion +specifications. Time conversion specifications are two-character +sequences beginning with `<<%>>' (use `<<%%>>' to include a percent +sign in the output). Each defined conversion specification selects a +field of calendar time data from <<*<[timp]>>>, and converts it to a +string in one of the following ways: + +o+ +o %a +An abbreviation for the day of the week. + +o %A +The full name for the day of the week. + +o %b +An abbreviation for the month name. + +o %B +The full name of the month. + +o %c +A string representing the complete date and time, in the form +. Mon Apr 01 13:13:13 1992 + +o %d +The day of the month, formatted with two digits. + +o %H +The hour (on a 24-hour clock), formatted with two digits. + +o %I +The hour (on a 12-hour clock), formatted with two digits. + +o %j +The count of days in the year, formatted with three digits +(from `<<001>>' to `<<366>>'). + +o %m +The month number, formatted with two digits. + +o %M +The minute, formatted with two digits. + +o %p +Either `<<AM>>' or `<<PM>>' as appropriate. + +o %S +The second, formatted with two digits. + +o %U +The week number, formatted with two digits (from `<<00>>' to `<<53>>'; +week number 1 is taken as beginning with the first Sunday in a year). +See also <<%W>>. + +o %w +A single digit representing the day of the week: Sunday is day <<0>>. + +o %W +Another version of the week number: like `<<%U>>', but counting week 1 +as beginning with the first Monday in a year. + +o +o %x +A string representing the complete date, in a format like +. Mon Apr 01 1992 + +o %X +A string representing the full time of day (hours, minutes, and +seconds), in a format like +. 13:13:13 + +o %y +The last two digits of the year. + +o %Y +The full year, formatted with four digits to include the century. + +o %Z +Defined by ANSI C as eliciting the time zone if available; it is not +available in this implementation (which accepts `<<%Z>>' but generates +no output for it). + +o %% +A single character, `<<%>>'. +o- + +RETURNS +When the formatted time takes up no more than <[maxsize]> characters, +the result is the length of the formatted string. Otherwise, if the +formatting operation was abandoned due to lack of room, the result is +<<0>>, and the string starting at <[s]> corresponds to just those +parts of <<*<[format]>>> that could be completely filled in within the +<[maxsize]> limit. + +PORTABILITY +ANSI C requires <<strftime>>, but does not specify the contents of +<<*<[s]>>> when the formatted string would require more than +<[maxsize]> characters. + +<<strftime>> requires no supporting OS subroutines. +*/ + +#include <stddef.h> +#include <stdio.h> +#include <time.h> + +static _CONST int dname_len[7] = +{6, 6, 7, 9, 8, 6, 8}; + +static _CONST char *_CONST dname[7] = +{"Sunday", "Monday", "Tuesday", "Wednesday", + "Thursday", "Friday", "Saturday"}; + +static _CONST int mname_len[12] = +{7, 8, 5, 5, 3, 4, 4, 6, 9, 7, 8, 8}; + +static _CONST char *_CONST mname[12] = +{"January", "February", "March", "April", + "May", "June", "July", "August", "September", "October", "November", + "December"}; + +size_t +_DEFUN (strftime, (s, maxsize, format, tim_p), + char *s _AND + size_t maxsize _AND + _CONST char *format _AND + _CONST struct tm *tim_p) +{ + size_t count = 0; + int i; + + for (;;) + { + while (*format && *format != '%') + { + if (count < maxsize - 1) + s[count++] = *format++; + else + return 0; + } + + if (*format == '\0') + break; + + format++; + switch (*format) + { + case 'a': + for (i = 0; i < 3; i++) + { + if (count < maxsize - 1) + s[count++] = + dname[tim_p->tm_wday][i]; + else + return 0; + } + break; + case 'A': + for (i = 0; i < dname_len[tim_p->tm_wday]; i++) + { + if (count < maxsize - 1) + s[count++] = + dname[tim_p->tm_wday][i]; + else + return 0; + } + break; + case 'b': + for (i = 0; i < 3; i++) + { + if (count < maxsize - 1) + s[count++] = + mname[tim_p->tm_mon][i]; + else + return 0; + } + break; + case 'B': + for (i = 0; i < mname_len[tim_p->tm_mon]; i++) + { + if (count < maxsize - 1) + s[count++] = + mname[tim_p->tm_mon][i]; + else + return 0; + } + break; + case 'c': + if (count < maxsize - 24) + { + for (i = 0; i < 3; i++) + s[count++] = + dname[tim_p->tm_wday][i]; + s[count++] = ' '; + for (i = 0; i < 3; i++) + s[count++] = + mname[tim_p->tm_mon][i]; + + sprintf (&s[count], + " %.2d %2.2d:%2.2d:%2.2d %.4d", + tim_p->tm_mday, tim_p->tm_hour, + tim_p->tm_min, + tim_p->tm_sec, 1900 + + tim_p->tm_year); + count += 17; + } + else + return 0; + break; + case 'd': + if (count < maxsize - 2) + { + sprintf (&s[count], "%.2d", + tim_p->tm_mday); + count += 2; + } + else + return 0; + break; + case 'H': + if (count < maxsize - 2) + { + sprintf (&s[count], "%2.2d", + tim_p->tm_hour); + count += 2; + } + else + return 0; + break; + case 'I': + if (count < maxsize - 2) + { + if (tim_p->tm_hour == 0 || + tim_p->tm_hour == 12) + { + s[count++] = '1'; + s[count++] = '2'; + } + else + { + sprintf (&s[count], "%.2d", + tim_p->tm_hour % 12); + count += 2; + } + } + else + return 0; + break; + case 'j': + if (count < maxsize - 3) + { + sprintf (&s[count], "%.3d", + tim_p->tm_yday + 1); + count += 3; + } + else + return 0; + break; + case 'm': + if (count < maxsize - 2) + { + sprintf (&s[count], "%.2d", + tim_p->tm_mon + 1); + count += 2; + } + else + return 0; + break; + case 'M': + if (count < maxsize - 2) + { + sprintf (&s[count], "%2.2d", + tim_p->tm_min); + count += 2; + } + else + return 0; + break; + case 'p': + if (count < maxsize - 2) + { + if (tim_p->tm_hour < 12) + s[count++] = 'A'; + else + s[count++] = 'P'; + + s[count++] = 'M'; + } + else + return 0; + break; + case 'S': + if (count < maxsize - 2) + { + sprintf (&s[count], "%2.2d", + tim_p->tm_sec); + count += 2; + } + else + return 0; + break; + case 'U': + if (count < maxsize - 2) + { + sprintf (&s[count], "%2.2d", + (tim_p->tm_yday + 7 - + tim_p->tm_wday) / 7); + count += 2; + } + else + return 0; + break; + case 'w': + if (count < maxsize - 1) + { + sprintf (&s[count], "%1.1d", + tim_p->tm_wday); + count++; + } + else + return 0; + break; + case 'W': + if (count < maxsize - 2) + { + sprintf (&s[count], "%2.2d", + (tim_p->tm_yday + ((8 - + tim_p->tm_wday) % 7)) / 7); + count += 2; + } + else + return 0; + break; + case 'x': + if (count < maxsize - 15) + { + for (i = 0; i < 3; i++) + s[count++] = + dname[tim_p->tm_wday][i]; + s[count++] = ' '; + for (i = 0; i < 3; i++) + s[count++] = + mname[tim_p->tm_mon][i]; + + sprintf (&s[count], + " %.2d %.4d", tim_p->tm_mday, + 1900 + tim_p->tm_year); + count += 8; + } + else + return 0; + break; + case 'X': + if (count < maxsize - 8) + { + sprintf (&s[count], + "%2.2d:%2.2d:%2.2d", + tim_p->tm_hour, tim_p->tm_min, + tim_p->tm_sec); + count += 8; + } + else + return 0; + break; + case 'y': + if (count < maxsize - 2) + { + /* The year could be greater than 100, so we need the value + modulo 100. The year could be negative, so we need to + correct for a possible negative remainder. */ + sprintf (&s[count], "%2.2d", + (tim_p->tm_year % 100 + 100) % 100); + count += 2; + } + else + return 0; + break; + case 'Y': + if (count < maxsize - 4) + { + sprintf (&s[count], "%.4d", + 1900 + tim_p->tm_year); + count += 4; + } + else + return 0; + break; + case 'Z': + break; + case '%': + if (count < maxsize - 1) + s[count++] = '%'; + else + return 0; + break; + } + if (*format) + format++; + else + break; + } + s[count] = '\0'; + + return count; +} |