[ascii.git] / fdprintf.c

/*
  File name        : fprintf.c
  Date of creation : 05/12/2022
  Version          : 1.0
  Copyright        : Soft'n'design
  Author           : Laurent Mazet <mazet@softndesign.org>

  Description      : This file contains embedded printf

  History          :
  - initial version
*/

#include <stdarg.h>
#include <stdint.h>
#include <unistd.h>

#include "fdprintf.h"

int _fd_stdout = STDOUT_FILENO;
int _fd_stderr = STDERR_FILENO;

unsigned int nextpow (unsigned int x, int base) {
    unsigned int n = 0;
    while (x) {
        n++;
        x = x / base;
    }
    return (n == 0) ? 1 : n;
}

/* simple fprintf function */

int fdprintf (int fd, const char *fmt, ...)
{
    char buffer[1024 + 1] = { 0 };
    char *str = buffer;

    va_list ap;
    va_start (ap, fmt);
    while (*fmt) {
        char *s;
        int d = 0;
        unsigned int u;
        char c = *fmt++;

        /* copy standard char */
        if (c != '%') {
            *str++ = c;
        } else {
            int t = 0;
	        char w = '0';
            int i, sz = 0;
            void *p = NULL;

            /* stamp */
            if ((*fmt == ' ') || (*fmt == '0')) {
                w = *fmt++;
            }

            /* size */
            if ((*fmt >= '1') && (*fmt <= '9')) {
                sz = *fmt++ - '0';
            }

            /* process format char */
            switch (*fmt++) {
            case 'c': /* char */
                c = (char) va_arg (ap, int);
                *str++ = c;
                break;
            case 'd': /* int */
                d = va_arg (ap, int);
                if (d < 0) {
                    *str++ = '-';
                    d = -d;
                }
                t = 1;
                /* fall through */
            case 'u': /* unsigned int */
                u = (t) ? (unsigned int)d : va_arg (ap, unsigned int);
                for (i = nextpow (u, 10), s = str; i > 0; i--, s++) {
                    str[i - 1] = '0' + (u % 10);
                    u /= 10;
                }
                str = s;
                break;
            case 'p': /* pointer */
                *str++ = '0';
                *str++ = 'x';
                w = '0';
                sz = sizeof (void *) * 2;
                p = va_arg (ap, void *);
                /* fall through */
            case 'x': /* integer hexa */
                if (!p) {
                    u = va_arg (ap, unsigned int);
                    if (sz == 0) {
                        sz = nextpow (u, 16);
                    }
                } else {
                    u = (uintptr_t)p;
                }
                for (i = sz, t = 1; i > 0; i--) {
                    char x = (char)((u >> (i * 4 - 4)) & 0xf);
                    if ((t == 1) && (x == 0)) {
                        *str++ = w;
                    } else {
                        *str++ = (x > 9) ? 'a' + x - 10 : '0' + x;
                        t = 0;
                    }
                }
                break;
            case 's': /* string */
                s = va_arg (ap, char *);
                while (s && *s)
                    *str++ = *s++;
                break;
            default:
                *str++ = '?';
            }
        }
    }
    va_end (ap);

    /* output string */
    int n = str - buffer;
    if (n < (int)sizeof (buffer) - 1) {
        return write (fd, buffer, n);
    }
    return 0;
}

/* vim: set ts=4 sw=4 et: */
Commit	Line	Data
1968fc94 LM	1	/*
	2	File name : fprintf.c
	3	Date of creation : 05/12/2022
	4	Version : 1.0
	5	Copyright : Soft'n'design
	6	Author : Laurent Mazet <mazet@softndesign.org>
	7
	8	Description : This file contains embedded printf
	9
	10	History :
	11	- initial version
	12	*/
	13
	14	#include <stdarg.h>
	15	#include <stdint.h>
	16	#include <unistd.h>
	17
	18	#include "fdprintf.h"
	19
	20	int _fd_stdout = STDOUT_FILENO;
	21	int _fd_stderr = STDERR_FILENO;
	22
	23	unsigned int nextpow (unsigned int x, int base) {
	24	unsigned int n = 0;
	25	while (x) {
	26	n++;
	27	x = x / base;
	28	}
	29	return (n == 0) ? 1 : n;
	30	}
	31
	32	/* simple fprintf function */
	33
	34	int fdprintf (int fd, const char *fmt, ...)
	35	{
	36	char buffer[1024 + 1] = { 0 };
	37	char *str = buffer;
	38
	39	va_list ap;
	40	va_start (ap, fmt);
	41	while (*fmt) {
	42	char *s;
	43	int d = 0;
	44	unsigned int u;
	45	char c = *fmt++;
	46
	47	/* copy standard char */
	48	if (c != '%') {
	49	*str++ = c;
	50	} else {
	51	int t = 0;
	52	char w = '0';
	53	int i, sz = 0;
	54	void *p = NULL;
	55
	56	/* stamp */
	57	if ((fmt == ' ') \|\| (fmt == '0')) {
	58	w = *fmt++;
	59	}
	60
	61	/* size */
	62	if ((fmt >= '1') && (fmt <= '9')) {
	63	sz = *fmt++ - '0';
	64	}
65
66	/* process format char */
67	switch (*fmt++) {
68	case 'c': /* char */
69	c = (char) va_arg (ap, int);
70	*str++ = c;
71	break;
72	case 'd': /* int */
73	d = va_arg (ap, int);
74	if (d < 0) {
75	*str++ = '-';
76	d = -d;
77	}
78	t = 1;
79	/* fall through */
80	case 'u': /* unsigned int */
81	u = (t) ? (unsigned int)d : va_arg (ap, unsigned int);
82	for (i = nextpow (u, 10), s = str; i > 0; i--, s++) {
83	str[i - 1] = '0' + (u % 10);
84	u /= 10;
85	}
86	str = s;
87	break;
88	case 'p': /* pointer */
89	*str++ = '0';
90	*str++ = 'x';
91	w = '0';
92	sz = sizeof (void ) 2;
93	p = va_arg (ap, void *);
94	/* fall through */
95	case 'x': /* integer hexa */
96	if (!p) {
97	u = va_arg (ap, unsigned int);
98	if (sz == 0) {
99	sz = nextpow (u, 16);
100	}
101	} else {
102	u = (uintptr_t)p;
103	}
104	for (i = sz, t = 1; i > 0; i--) {
105	char x = (char)((u >> (i * 4 - 4)) & 0xf);
106	if ((t == 1) && (x == 0)) {
107	*str++ = w;
108	} else {
109	*str++ = (x > 9) ? 'a' + x - 10 : '0' + x;
110	t = 0;
111	}
112	}
113	break;
114	case 's': /* string */
115	s = va_arg (ap, char *);
116	while (s && *s)
117	str++ = s++;
118	break;
119	default:
120	*str++ = '?';
121	}
122	}
123	}
124	va_end (ap);
125
126	/* output string */
127	int n = str - buffer;
128	if (n < (int)sizeof (buffer) - 1) {
129	return write (fd, buffer, n);
130	}
131	return 0;
132	}
133
134	/* vim: set ts=4 sw=4 et: */