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| author | Robert Morris <rtm@csail.mit.edu> | 2019-06-11 09:57:14 -0400 |
|---|---|---|
| committer | Robert Morris <rtm@csail.mit.edu> | 2019-06-11 09:57:14 -0400 |
| commit | 5753553213df8f9de851adb68377db43faecb91f (patch) | |
| tree | 3b629ff54897fca414146677532cb459a2ed11ba /printf.c | |
| parent | 91ba81110acd3163f7de3580b677eece0c57f5e7 (diff) | |
| download | xv6-labs-5753553213df8f9de851adb68377db43faecb91f.tar.gz xv6-labs-5753553213df8f9de851adb68377db43faecb91f.tar.bz2 xv6-labs-5753553213df8f9de851adb68377db43faecb91f.zip | |
separate source into kernel/ user/ mkfs/
Diffstat (limited to 'printf.c')
| -rw-r--r-- | printf.c | 95 |
1 files changed, 0 insertions, 95 deletions
diff --git a/printf.c b/printf.c deleted file mode 100644 index c820305..0000000 --- a/printf.c +++ /dev/null @@ -1,95 +0,0 @@ -#include "types.h" -#include "stat.h" -#include "user.h" - -#include <stdarg.h> - -static char digits[] = "0123456789ABCDEF"; - -static void -putc(int fd, char c) -{ - write(fd, &c, 1); -} - -static void -printint(int fd, int xx, int base, int sgn) -{ - char buf[16]; - int i, neg; - uint x; - - neg = 0; - if(sgn && xx < 0){ - neg = 1; - x = -xx; - } else { - x = xx; - } - - i = 0; - do{ - buf[i++] = digits[x % base]; - }while((x /= base) != 0); - if(neg) - buf[i++] = '-'; - - while(--i >= 0) - putc(fd, buf[i]); -} - -static void -printptr(int fd, uint64 x) { - int i; - putc(fd, '0'); - putc(fd, 'x'); - for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4) - putc(fd, digits[x >> (sizeof(uint64) * 8 - 4)]); -} - -// Print to the given fd. Only understands %d, %x, %p, %s. -void -printf(int fd, const char *fmt, ...) -{ - va_list ap; - char *s; - int c, i, state; - - va_start(ap, fmt); - state = 0; - for(i = 0; fmt[i]; i++){ - c = fmt[i] & 0xff; - if(state == 0){ - if(c == '%'){ - state = '%'; - } else { - putc(fd, c); - } - } else if(state == '%'){ - if(c == 'd'){ - printint(fd, va_arg(ap, int), 10, 1); - } else if(c == 'x') { - printint(fd, va_arg(ap, int), 16, 0); - } else if(c == 'p') { - printptr(fd, va_arg(ap, uint64)); - } else if(c == 's'){ - s = va_arg(ap, char*); - if(s == 0) - s = "(null)"; - while(*s != 0){ - putc(fd, *s); - s++; - } - } else if(c == 'c'){ - putc(fd, va_arg(ap, uint)); - } else if(c == '%'){ - putc(fd, c); - } else { - // Unknown % sequence. Print it to draw attention. - putc(fd, '%'); - putc(fd, c); - } - state = 0; - } - } -} |