diff options
| -rw-r--r-- | battfmt.c | 28 | ||||
| -rw-r--r-- | beatform.c | 26 | ||||
| -rw-r--r-- | bgetceofindeed.c | 23 | ||||
| -rw-r--r-- | bgetding.c | 46 | ||||
| -rw-r--r-- | bincoeff.c | 63 | ||||
| -rw-r--r-- | bitround.c | 25 | ||||
| -rw-r--r-- | bracketop.c | 11 | ||||
| -rw-r--r-- | colgrad.c | 83 | ||||
| -rw-r--r-- | consreadnum.c | 17 | ||||
| -rw-r--r-- | const.c | 15 | ||||
| -rw-r--r-- | constructor.c | 49 | ||||
| -rw-r--r-- | dichotomy.c | 36 | ||||
| -rw-r--r-- | doubleparse.c | 20 | ||||
| -rw-r--r-- | dprom.c | 10 | ||||
| -rw-r--r-- | dynarray.c | 12 | ||||
| -rw-r--r-- | dynsubscript.c | 25 | ||||
| -rw-r--r-- | extorlocal.c | 19 | ||||
| -rw-r--r-- | extorlocal.s | 12 | ||||
| -rw-r--r-- | extorlocalmain.c | 11 | ||||
| -rw-r--r-- | frisvadonb.c | 110 | ||||
| -rw-r--r-- | gcd.c | 68 | ||||
| -rw-r--r-- | genrandname.c | 57 | ||||
| -rw-r--r-- | hashing.c | 85 | ||||
| -rw-r--r-- | hello.c | 9 | ||||
| -rw-r--r-- | hypotenuse.c | 59 | ||||
| -rw-r--r-- | imgp.c | 8 | ||||
| -rw-r--r-- | isptrmod.c | 27 | ||||
| -rw-r--r-- | matrixinv.c | 377 | ||||
| -rw-r--r-- | matrixmul.c | 53 | ||||
| -rw-r--r-- | minhello.c | 9 | ||||
| -rw-r--r-- | multibatt.c | 30 | ||||
| -rw-r--r-- | nhello.c | 15 | ||||
| -rw-r--r-- | nonrecurfact.c | 58 | ||||
| -rw-r--r-- | prec.c | 14 | ||||
| -rw-r--r-- | prec2.c | 15 | ||||
| -rw-r--r-- | printdec.c | 60 | ||||
| -rw-r--r-- | qrot.c | 94 | ||||
| -rw-r--r-- | que.c | 70 | ||||
| -rw-r--r-- | ret.c | 19 | ||||
| -rw-r--r-- | rev.c | 48 | ||||
| -rw-r--r-- | revdonewrong.c | 42 | ||||
| -rw-r--r-- | reverse.c | 42 | ||||
| -rw-r--r-- | rounding.c | 37 | ||||
| -rw-r--r-- | rpn.c | 51 | ||||
| -rw-r--r-- | seeking.c | 24 | ||||
| -rw-r--r-- | signed.c | 14 | ||||
| -rw-r--r-- | sizeof2d.c | 11 | ||||
| -rw-r--r-- | smiley.pic | 26 | ||||
| -rw-r--r-- | snprintandf.c | 18 | ||||
| -rw-r--r-- | snprinting.c | 13 | ||||
| -rw-r--r-- | spranimate.c | 98 | ||||
| -rw-r--r-- | strlen.c | 11 | ||||
| -rw-r--r-- | structcmp.c | 32 | ||||
| -rw-r--r-- | structvsarray.c | 61 | ||||
| -rw-r--r-- | sum.s | 4 | ||||
| -rw-r--r-- | sumain.c | 14 | ||||
| -rw-r--r-- | t.c | 48 | ||||
| -rw-r--r-- | test.c | 14 | ||||
| -rw-r--r-- | tok.c | 16 | ||||
| -rw-r--r-- | transpose.c | 49 | ||||
| -rw-r--r-- | vec.c | 26 |
61 files changed, 2467 insertions, 0 deletions
diff --git a/battfmt.c b/battfmt.c new file mode 100644 index 0000000..14e0832 --- /dev/null +++ b/battfmt.c @@ -0,0 +1,28 @@ +#include <u.h> +#include <libc.h> +#include <ctype.h> + +void +battfmt(char *buf, long buflen) +{ + char *s; + + for(s = buf; (s-buf) < buflen; s++) + if(!isdigit(*s)){ + for(;(s-buf) < buflen; s++) + *s = '\0'; + break; + } +} + +void +main(void) +{ + char str[] = "30 m"; + + battfmt(str, 4); + + print("%s\n", str); + + exits("done"); +} diff --git a/beatform.c b/beatform.c new file mode 100644 index 0000000..b7ff9f7 --- /dev/null +++ b/beatform.c @@ -0,0 +1,26 @@ +#include <u.h> +#include <libc.h> + +uvlong +next(uvlong t) +{ + print("t0: %llud ", t); + t = t * 8000 / 44100; + print("t1: %llud ", t); + t = t*(42&t>>10); + print("t2: %llud ", t); + print("t3: %llud ", t<<8); + return t<<8; +} + +void +main() +{ + uvlong t; + short sl; + + for(t = 20000;; t++){ + sl = next(t); + print("%2d\t", sl); + } +} diff --git a/bgetceofindeed.c b/bgetceofindeed.c new file mode 100644 index 0000000..bc79162 --- /dev/null +++ b/bgetceofindeed.c @@ -0,0 +1,23 @@ +#include <u.h> +#include <libc.h> +#include <bio.h> + +void +main() +{ + Biobuf *bin; + char c; + + bin = Bfdopen(0, OREAD); + if(bin == nil) + sysfatal("Bfdopen: %r"); + while((c = Bgetc(bin)) != Beof) + ; + USED(c); + c = Bgetc(bin); + if(c == Beof) + print("eof indeed\n"); + else + print("no eof after eof\n"); + exits(0); +} diff --git a/bgetding.c b/bgetding.c new file mode 100644 index 0000000..cc427e2 --- /dev/null +++ b/bgetding.c @@ -0,0 +1,46 @@ +#include <u.h> +#include <libc.h> +#include <bio.h> + +typedef struct +{ + double x, y, z; +} Vec; + +void +usage(void) +{ + fprint(2, "usage: %s [file]\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + Biobuf *bin; + Vec v; + int fd, r; + + fd = 0; + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc > 1) + usage(); + else if(argc == 1){ + fd = open(argv[0], OREAD); + if(fd < 0) + sysfatal("open: %r"); + } + bin = Bfdopen(fd, OREAD); + if(bin == nil) + sysfatal("Bfdopen: %r"); + r = Bgetd(bin, &v.x); + print("got %g r=%d\n", v.x, r); + r = Bgetd(bin, &v.y); + print("got %g r=%d\n", v.y, r); + r = Bgetd(bin, &v.z); + print("got %g r=%d\n", v.z, r); + Bterm(bin); + exits(0); +} diff --git a/bincoeff.c b/bincoeff.c new file mode 100644 index 0000000..624bb19 --- /dev/null +++ b/bincoeff.c @@ -0,0 +1,63 @@ +#include <u.h> +#include <libc.h> + +vlong t0, Δt; + +double +fac(double n) +{ + double Π; + + Π = 1; + assert(n > 0); + while(n > 1) + Π *= n--; + return Π; +} + +double +bincoeff(double n, double k) +{ + assert(k <= n); + return fac(n)/(fac(k)*fac(n-k)); +} + +double +bincoeffmul(double n, double k) +{ + double Π; + int i; + + assert(k <= n); + Π = 1; + for(i = 1; i <= k; i++) + Π *= (n + 1 - i)/i; + return Π; +} + +void +usage(void) +{ + fprint(2, "usage: bincoeff n k\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + double n, k, bc; + + if(argc != 3) + usage(); + n = strtod(argv[1], nil); + k = strtod(argv[2], nil); + t0 = nsec(); + bc = bincoeff(n, k); + Δt = nsec()-t0; + print("method 1: %g (%lldns)\n", bc, Δt); + t0 = nsec(); + bc = bincoeffmul(n, k); + Δt = nsec()-t0; + print("method 2: %g (%lldns)\n", bc, Δt); + exits(nil); +} diff --git a/bitround.c b/bitround.c new file mode 100644 index 0000000..4602387 --- /dev/null +++ b/bitround.c @@ -0,0 +1,25 @@ +#include <u.h> +#include <libc.h> + +#define round(s, sz) ((s)+((sz)-1)&~((sz)-1)) + +static void +usage(void) +{ + fprint(2, "usage: bitround number\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int i; + + if(argc != 2) + usage(); + i = strtol(argv[1], nil, 0); + print("i0 %b (%d)\n", i, i); + i = round(i, sizeof(int)); + print("i1 %b (%d)\n", i, i); + exits(0); +} diff --git a/bracketop.c b/bracketop.c new file mode 100644 index 0000000..f46849b --- /dev/null +++ b/bracketop.c @@ -0,0 +1,11 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + int a[] = {1, 2}; + + print("%d\n", 1[a]); + exits(nil); +} diff --git a/colgrad.c b/colgrad.c new file mode 100644 index 0000000..a122a49 --- /dev/null +++ b/colgrad.c @@ -0,0 +1,83 @@ +#include <u.h> +#include <libc.h> +#include <draw.h> + +enum { SEC = 1000 }; + +enum { + Cred, + Cgrn, + Cblu, + + Cgx, + Cgy, + Cend +}; +Image *col[Cend]; + +int dx, dy; + +void * +emalloc(ulong n) +{ + void *p; + + p = malloc(n); + if(p == nil) + sysfatal("malloc: %r"); + memset(p, 0, n); + setmalloctag(p, getcallerpc(&n)); + return p; +} + +Image * +eallocimage(Display *d, Rectangle r, ulong chan, int repl, ulong col) +{ + Image *i; + + i = allocimage(d, r, chan, repl, col); + if(i == nil) + sysfatal("allocimage: %r"); + return i; +} + +void +usage(void) +{ + fprint(2, "usage: colgrad\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int i; + uchar *gx, *gy; + + ARGBEGIN{ + default: usage(); + }ARGEND; + + if(initdraw(nil, nil, "colgrad") < 0) + sysfatal("initdraw: %r"); + dx = Dx(screen->r), dy = Dy(screen->r); + col[Cred] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DRed); + col[Cgrn] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DGreen); + col[Cblu] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DBlue); + col[Cgx] = eallocimage(display, Rect(0, 0, dx, 1), GREY8, 1, DNofill); + col[Cgy] = eallocimage(display, Rect(0, 0, 1, dy), GREY8, 1, DNofill); + gx = emalloc(dx); + gy = emalloc(dy); + for(i = 0; i < dx; i++) + gx[i] = 255.0 * i/(dx-1); + for(i = 0; i < dy; i++) + gy[i] = 255.0 * i/(dy-1); + loadimage(col[Cgx], col[Cgx]->r, gx, dx); + loadimage(col[Cgy], col[Cgy]->r, gy, dy); + draw(screen, screen->r, col[Cred], nil, ZP); + draw(screen, screen->r, col[Cgrn], col[Cgx], ZP); + draw(screen, screen->r, col[Cblu], col[Cgy], ZP); + flushimage(display, 1); + sleep(5*SEC); + exits(0); +} diff --git a/consreadnum.c b/consreadnum.c new file mode 100644 index 0000000..2e4f853 --- /dev/null +++ b/consreadnum.c @@ -0,0 +1,17 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char tmp[64]; + int size; + + size = 2*1024*1024*1024; + if(size > sizeof tmp || size < 0) + size = sizeof tmp; + snprint(tmp, sizeof tmp, "%*lud", size-1, 409234UL); + tmp[size-1] = ' '; + print("%s\n", tmp); + exits(nil); +} @@ -0,0 +1,15 @@ +#include <u.h> +#include <libc.h> + +char *p = "gooseberry"; +char a[] = "gooseberry"; + +void +main() +{ + print("%s\n%s\n", p, a); + strncpy(p, "black", 5); + strncpy(a, "black", 5); + print("%s\n%s\n", p, a); + exits(nil); +} diff --git a/constructor.c b/constructor.c new file mode 100644 index 0000000..3ecff2d --- /dev/null +++ b/constructor.c @@ -0,0 +1,49 @@ +#include <u.h> +#include <libc.h> + +typedef struct Point Point; +struct Point +{ + int x, y; +}; + +typedef struct Pointd Pointd; +struct Pointd +{ + double x, y, w; +}; + +Point +Pt(int x, int y) +{ + return (Point){x, y}; +} + +Pointd +Ptd(double x, double y, double w) +{ + return (Pointd){x, y, w}; +} + +vlong t0; + +void +main() +{ + Point p; + Pointd pd; + + t0 = nsec(); + p = (Point){2, 3}; + fprint(2, "p1 %lldnsec\n", nsec()-t0); + t0 = nsec(); + p = Pt(2, 3); + fprint(2, "p2 %lldnsec\n", nsec()-t0); + t0 = nsec(); + pd = (Pointd){2.0, 3.0, 1.0}; + fprint(2, "pd1 %lldnsec\n", nsec()-t0); + t0 = nsec(); + pd = Ptd(2.0, 3.0, 1.0); + fprint(2, "pd2 %lldnsec\n", nsec()-t0); + exits(0); +} diff --git a/dichotomy.c b/dichotomy.c new file mode 100644 index 0000000..5eea1e0 --- /dev/null +++ b/dichotomy.c @@ -0,0 +1,36 @@ +#include <u.h> +#include <libc.h> + +void * +emalloc(ulong n) +{ + void *p; + + p = malloc(n); + if(p == nil) + sysfatal("malloc: %r"); + memset(p, 0, n); + setmalloctag(p, getcallerpc(&n)); + return p; +} + +char **listp; +char *lista[] = { + "just", + "a", + "couple", + "of", + "words" +}; +char s[] = "ignore this and keep going"; + +void +main() +{ + print("listp size pre-alloc: %d\n", sizeof(listp)); + listp = emalloc(4096); + print("listp size post-alloc: %d\n", sizeof(listp)); + print("lista size: %d & len: %d\n", sizeof(lista), nelem(lista)); + print("s size: %d & len: %ld\n", sizeof(s), strlen(s)); + exits(0); +} diff --git a/doubleparse.c b/doubleparse.c new file mode 100644 index 0000000..497b904 --- /dev/null +++ b/doubleparse.c @@ -0,0 +1,20 @@ +#include <u.h> +#include <libc.h> +#include <ctype.h> + +void +main() +{ + char *s, buf[512]; + double n[2]; + + read(0, buf, sizeof(buf)-1); + buf[sizeof(buf)-1] = 0; + s = buf; + n[0] = strtod(s, &s); + while(isspace(*++s)) + ; + n[1] = strtod(s, &s); + print("n0: %g\nn1: %g\n", n[0], n[1]); + exits(0); +} @@ -0,0 +1,10 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + if(0.00001 > 0) print("ok\n"); + else print("ko\n"); + exits(0); +} diff --git a/dynarray.c b/dynarray.c new file mode 100644 index 0000000..5b296a1 --- /dev/null +++ b/dynarray.c @@ -0,0 +1,12 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char buf[]; + + buf = malloc(128); + print("%d\n", nelem(buf)); + exits(nil); +} diff --git a/dynsubscript.c b/dynsubscript.c new file mode 100644 index 0000000..e432c22 --- /dev/null +++ b/dynsubscript.c @@ -0,0 +1,25 @@ +#include <u.h> +#include <libc.h> + +typedef struct Num Num; + +struct Num { + int v; +}; + +Num one = {1}; +Num three = {3}; +Num fourteen = {14}; + +char *list[] = { +[one.v] "ein", +[three.v] "drei", +[fourteen.v] "vierzehn" +}; + +void +main() +{ + print("%s\n", list[one.v]); + exits(0); +} diff --git a/extorlocal.c b/extorlocal.c new file mode 100644 index 0000000..e27f1ae --- /dev/null +++ b/extorlocal.c @@ -0,0 +1,19 @@ +#include <u.h> +#include <libc.h> + +static char s[] = "hello "; +char t[] = "world\n"; + +void +greet(void) +{ + write(1, s, 6); + write(1, t, 6); +} + +void +main() +{ + greet(); + //exits(0); +} diff --git a/extorlocal.s b/extorlocal.s new file mode 100644 index 0000000..cf63e37 --- /dev/null +++ b/extorlocal.s @@ -0,0 +1,12 @@ +DATA s+0(SB)/8,$"hello wo" +DATA s+8(SB)/4,$"rld\n" +GLOBL s(SB),$13 + +TEXT greet(SB), $32 + MOVL $1, BP + MOVQ $s+0(SB), DI + MOVQ DI, 8(SP) + MOVL $12, DI + MOVL DI, 16(SP) + CALL write(SB) + RET diff --git a/extorlocalmain.c b/extorlocalmain.c new file mode 100644 index 0000000..d23a54d --- /dev/null +++ b/extorlocalmain.c @@ -0,0 +1,11 @@ +#include <u.h> +#include <libc.h> + +void greet(void); + +void +main() +{ + greet(); + //exits(0); +} diff --git a/frisvadonb.c b/frisvadonb.c new file mode 100644 index 0000000..2eed155 --- /dev/null +++ b/frisvadonb.c @@ -0,0 +1,110 @@ +/* + * Implementation of the techniques described in †. + * + * † Tom Duff, James Burgess, Per Christensen, Christophe Hery, Andrew + * Kensler, Max Liani, and Ryusuke Villemin, Building an Orthonormal + * Basis, Revisited, Journal of Computer Graphics Techniques (JCGT), vol. 6, + * no. 1, 1-8, 2017. Available online at http://jcgt.org/published/0006/01/01/ +*/ + +#include <u.h> +#include <libc.h> + +typedef struct Vec Vec; +struct Vec { + double x, y, z; +}; + +vlong t0; + +Vec +Vect(double x, double y, double z) +{ + return (Vec){x, y, z}; +} + +void +frisvadONB(Vec b[3]) +{ + double p, q; + + if(b[0].z < -0.9999999){ /* handle singularity */ + b[1] = Vect(0, -1, 0); + b[2] = Vect(-1, 0, 0); + return; + } + p = 1/(1 + b[0].z); + q = -b[0].x*b[0].y*p; + b[1] = Vect(1 - b[0].x*b[0].x*p, q, -b[0].x); + b[2] = Vect(q, 1 - b[0].y*b[0].y*p, -b[0].y); +} + +void +revisedONB(Vec b[3]) +{ + double p, q; + + if(b[0].z < 0){ + p = 1/(1 - b[0].z); + q = b[0].x*b[0].y*p; + b[1] = Vect(1 - b[0].x*b[0].x*p, -q, b[0].x); + b[2] = Vect(q, b[0].y*b[0].y*p - 1, -b[0].y); + return; + } + p = 1/(1 + b[0].z); + q = -b[0].x*b[0].y*p; + b[1] = Vect(1 - b[0].x*b[0].x*p, q, -b[0].x); + b[2] = Vect(q, 1 - b[0].y*b[0].y*p, -b[0].y); +} + +void +revisedaONB(Vec b[3]) +{ + double p, q, σ; + + σ = b[0].z >= 0 ? 1 : -1; + p = -1/(σ + b[0].z); + q = b[0].x*b[0].y*p; + b[1] = Vect(1 + σ*b[0].x*b[0].x*p, σ*q, -σ*b[0].x); + b[2] = Vect(q, σ + b[0].y*b[0].y*p, -b[0].y); +} + +void +usage(void) +{ + fprint(2, "usage: %s x y z\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + Vec b[3]; + int i; + + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc != 3) + usage(); + b[0].x = strtod(argv[0], nil); + b[0].y = strtod(argv[1], nil); + b[0].z = strtod(argv[2], nil); + //b[0] = Vect(0.00038527316, 0.00038460016, -0.99999988079); + t0 = nsec(); + frisvadONB(b); + print("Frisvad's (took %lldns)\n", nsec()-t0); + for(i = 0; i < nelem(b); i++) + print("\tB%d [%g %g %g]\n", i+1, b[i].x, b[i].y, b[i].z); + t0 = nsec(); + revisedONB(b); + print("Revised (took %lldns)\n", nsec()-t0); + for(i = 0; i < nelem(b); i++) + print("\tB%d [%g %g %g]\n", i+1, b[i].x, b[i].y, b[i].z); + t0 = nsec(); + revisedaONB(b); + print("Revised Adv. (took %lldns)\n", nsec()-t0); + for(i = 0; i < nelem(b); i++) + print("\tB%d [%g %g %g]\n", i+1, b[i].x, b[i].y, b[i].z); + exits(nil); +} @@ -0,0 +1,68 @@ +#include <u.h> +#include <libc.h> + +enum { + Tgcd, + Tmod, + Te +}; +vlong t[Te]; +vlong t0; + +void +swap(int *a, int *b) +{ + int tmp; + + tmp = *a; + *a = *b; + *b = tmp; +} + +int +gcd(int u, int v) +{ + while(u > 0){ + if(u < v) + swap(&u, &v); + u = u-v; + } + return v; +} + +int +modgcd(int u, int v) +{ + while(u > 0){ + if(u < v) + swap(&u, &v); + u = u % v; + } + return v; +} + +void +usage(void) +{ + fprint(2, "usage: gcd num den\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int n, m; + + if(argc != 3) + sysfatal("not enough arguments"); + n = strtol(argv[1], nil, 0); + m = strtol(argv[2], nil, 0); + t0 = nsec(); + print("GCD %d %d = %d\n", n, m, gcd(n, m)); + t[Tgcd] = nsec()-t0; + t0 = nsec(); + print("MODGCD %d %d = %d\n", n, m, modgcd(n, m)); + t[Tmod] = nsec()-t0; + print("\tgcd: %lld | mod: %lld\n", t[Tgcd], t[Tmod]); + exits(nil); +} diff --git a/genrandname.c b/genrandname.c new file mode 100644 index 0000000..39ce199 --- /dev/null +++ b/genrandname.c @@ -0,0 +1,57 @@ +#include <u.h> +#include <libc.h> + +enum { + NF, + NM +}; + +typedef struct Name Name; +struct Name +{ + char *name; + int sex; +}; + +void +genrandname(char *d, ulong len) +{ + Name names[] = { + "mariana", NF, + "jerca", NF, + "repa", NF, + "jaca", NF, + "pinta", NF, + "manolo", NM, + "eustaquio", NM, + "aberroncho", NM, + "merovingio", NM, + "trudi", NM + }; + char *adjectives[] = { + "atropelladX", + "bacaladX", + "acojonadX", + "estrictX", + "diarreas", + "gordacX" + }, buf[256], *p; + int i; + + i = ntruerand(nelem(adjectives)); + snprint(buf, sizeof buf, "%s", adjectives[i]); + i = ntruerand(nelem(names)); + if((p = strchr(buf, 'X')) != nil) + *p = names[i].sex == NF ? 'a' : 'o'; + snprint(d, len, "%s%s", names[i].name, buf); +} + +void +main() +{ + char buf[256]; + + genrandname(buf, sizeof buf); + print("%s\n", buf); + exits(0); +} diff --git a/hashing.c b/hashing.c new file mode 100644 index 0000000..32e550f --- /dev/null +++ b/hashing.c @@ -0,0 +1,85 @@ +#include <u.h> +#include <libc.h> + +enum { + MULT = 31, + NHASH = 37, +}; + +uint +hash(char *s) +{ + uint h; + + h = 0; + while(*s != 0) + h = MULT * h + (uchar)*s++; + return h % NHASH; +} + +uint +djb2(char *s) +{ + uint h; + + h = 5381; + while(*s != 0) + h = ((h << 5) + h) + (uchar)*s++; + return h % NHASH; +} + +uint +djb2a(char *s) +{ + uint h; + + h = 5381; + while(*s != 0) + h = ((h << 5) + h) ^ (uchar)*s++; + return h % NHASH; +} + +uint +fnv1(char *s) +{ + uint h; + + h = 0x811c9dc5; + while(*s != 0) + h = (h*0x1000193) ^ (uchar)*s++; + return h % NHASH; +} + +uint +fnv1a(char *s) +{ + uint h; + + h = 0x811c9dc5; + while(*s != 0) + h = (h^(uchar)*s++) * 0x1000193; + return h % NHASH; +} + +void +usage(void) +{ + fprint(2, "usage: %s word\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc != 1) + usage(); + print("tpop:\t%ud\n", hash(*argv)); + print("djb2:\t%ud\n", djb2(*argv)); + print("djb2a:\t%ud\n", djb2a(*argv)); + print("fnv1:\t%ud\n", fnv1(*argv)); + print("fnv1a:\t%ud\n", fnv1a(*argv)); + exits(0); +} @@ -0,0 +1,9 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + print("Hello world\n"); + exits(0); +} diff --git a/hypotenuse.c b/hypotenuse.c new file mode 100644 index 0000000..ab4bb21 --- /dev/null +++ b/hypotenuse.c @@ -0,0 +1,59 @@ +#include <u.h> +#include <libc.h> + +double +hypot2(double p, double q) +{ + return sqrt(p*p + q*q); +} + +double +hypot3(double x, double y, double z) +{ + return sqrt(x*x + y*y + z*z); +} + +double +hypot3from2(double x, double y, double z) +{ + return hypot(hypot(x, z), y); +} + +void +usage(void) +{ + fprint(2, "usage: hypotenuse x y z\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + double x, y, z, r; + vlong t0, t; + + if(argc < 4) + usage(); + x = strtod(argv[1], nil); + y = strtod(argv[2], nil); + z = strtod(argv[3], nil); + /*print("\t2D\n"); + t0 = nsec(); + r = hypot2(x, y); + t = nsec(); + print("1st method: %g (%lld ns)\n", r, t-t0); + t0 = nsec(); + r = hypot(x, y); + t = nsec(); + print("2nd method: %g (%lld ns)\n", r, t-t0); + print("\t3D\n"); + t0 = nsec(); + r = hypot3(x, y, z); + t = nsec(); + print("1st method: %g (%lld ns)\n", r, t-t0);*/ + t0 = nsec(); + r = hypot3from2(x, y, z); + t = nsec(); + print("2nd method: %g (%lld ns)\n", r, t-t0); + exits(0); +} @@ -0,0 +1,8 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + +} diff --git a/isptrmod.c b/isptrmod.c new file mode 100644 index 0000000..912a66d --- /dev/null +++ b/isptrmod.c @@ -0,0 +1,27 @@ +#include <u.h> +#include <libc.h> + +/* + * this program proofs that effectively, pointer arguments are passed by + * value and its modification doesn't extend beyond the scope of the + * currently running procedure. + */ + +void +incptr(char *p) +{ + p += 3; + print("%s\n", p); +} + +void +main() +{ + char *s; + + s = "hi there!"; + print("%s\n", s); + incptr(s); + print("%s\n", s); + exits(0); +} diff --git a/matrixinv.c b/matrixinv.c new file mode 100644 index 0000000..b960c7c --- /dev/null +++ b/matrixinv.c @@ -0,0 +1,377 @@ +#include <u.h> +#include <libc.h> + +typedef double Matrix[3][3]; +typedef double Matrix3[4][4]; + +void +identity(Matrix m) +{ + memset(m, 0, 3*3*sizeof(double)); + m[0][0] = m[1][1] = m[2][2] = 1; +} + +void +addm(Matrix a, Matrix b) +{ + int i, j; + + for(i = 0; i < 3; i++) + for(j = 0; j < 3; j++) + a[i][j] += b[i][j]; +} + +void +subm(Matrix a, Matrix b) +{ + int i, j; + + for(i = 0; i < 3; i++) + for(j = 0; j < 3; j++) + a[i][j] -= b[i][j]; +} + +void +mulm(Matrix a, Matrix b) +{ + int i, j, k; + Matrix tmp; + + for(i = 0; i < 3; i++) + for(j = 0; j < 3; j++){ + tmp[i][j] = 0; + for(k = 0; k < 3; k++) + tmp[i][j] += a[i][k]*b[k][j]; + } + memmove(a, tmp, 3*3*sizeof(double)); +} + +void +smulm(Matrix m, double s) +{ + int i, j; + + for(i = 0; i < 3; i++) + for(j = 0; j < 3; j++) + m[i][j] *= s; +} + +double +detm(Matrix m) +{ + return m[0][0]*(m[1][1]*m[2][2] - m[1][2]*m[2][1])+ + m[0][1]*(m[1][2]*m[2][0] - m[1][0]*m[2][2])+ + m[0][2]*(m[1][0]*m[2][1] - m[1][1]*m[2][0]); +} + +double +tracem(Matrix m) +{ + return m[0][0] + m[1][1] + m[2][2]; +} + +/* Cayley-Hamilton */ +void +invertm(Matrix m) +{ + Matrix m², r; + double det, trm, trm²; + + det = detm(m); + if(det == 0) + return; /* singular matrices are not invertible */ + trm = tracem(m); + memmove(m², m, 3*3*sizeof(double)); + mulm(m², m²); + trm² = tracem(m²); + identity(r); + smulm(r, (trm*trm - trm²)/2); + smulm(m, trm); + subm(r, m); + addm(r, m²); + smulm(r, 1/det); + memmove(m, r, 3*3*sizeof(double)); +} + +/* Cramer's */ +void +adjm(Matrix m) +{ + Matrix tmp; + + tmp[0][0] = m[1][1]*m[2][2] - m[1][2]*m[2][1]; + tmp[0][1] = -m[0][1]*m[2][2] + m[0][2]*m[2][1]; + tmp[0][2] = m[0][1]*m[1][2] - m[0][2]*m[1][1]; + tmp[1][0] = -m[1][0]*m[2][2] + m[1][2]*m[2][0]; + tmp[1][1] = m[0][0]*m[2][2] - m[0][2]*m[2][0]; + tmp[1][2] = -m[0][0]*m[1][2] + m[0][2]*m[1][0]; + tmp[2][0] = m[1][0]*m[2][1] - m[1][1]*m[2][0]; + tmp[2][1] = -m[0][0]*m[2][1] + m[0][1]*m[2][0]; + tmp[2][2] = m[0][0]*m[1][1] - m[0][1]*m[1][0]; + memmove(m, tmp, 3*3*sizeof(double)); +} + +void +cinvertm(Matrix m) +{ + double det; + + det = detm(m); + if(det == 0) + return; /* singular matrices are not invertible */ + adjm(m); + smulm(m, 1/det); +} + +void +identity3(Matrix3 m) +{ + memset(m, 0, 4*4*sizeof(double)); + m[0][0] = m[1][1] = m[2][2] = m[3][3] = 1; +} + +void +addm3(Matrix3 a, Matrix3 b) +{ + int i, j; + + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++) + a[i][j] += b[i][j]; +} + +void +subm3(Matrix3 a, Matrix3 b) +{ + int i, j; + + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++) + a[i][j] -= b[i][j]; +} + +void +mulm3(Matrix3 a, Matrix3 b) +{ + int i, j, k; + Matrix3 tmp; + + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++){ + tmp[i][j] = 0; + for(k = 0; k < 4; k++) + tmp[i][j] += a[i][k]*b[k][j]; + } + memmove(a, tmp, 4*4*sizeof(double)); +} + +void +smulm3(Matrix3 m, double s) +{ + int i, j; + + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++) + m[i][j] *= s; +} + +double +detm3(Matrix3 m) +{ + return m[0][0]*(m[1][1]*(m[2][2]*m[3][3] - m[2][3]*m[3][2])+ + m[1][2]*(m[2][3]*m[3][1] - m[2][1]*m[3][3])+ + m[1][3]*(m[2][1]*m[3][2] - m[2][2]*m[3][1])) + -m[0][1]*(m[1][0]*(m[2][2]*m[3][3] - m[2][3]*m[3][2])+ + m[1][2]*(m[2][3]*m[3][0] - m[2][0]*m[3][3])+ + m[1][3]*(m[2][0]*m[3][2] - m[2][2]*m[3][0])) + +m[0][2]*(m[1][0]*(m[2][1]*m[3][3] - m[2][3]*m[3][1])+ + m[1][1]*(m[2][3]*m[3][0] - m[2][0]*m[3][3])+ + m[1][3]*(m[2][0]*m[3][1] - m[2][1]*m[3][0])) + -m[0][3]*(m[1][0]*(m[2][1]*m[3][2] - m[2][2]*m[3][1])+ + m[1][1]*(m[2][2]*m[3][0] - m[2][0]*m[3][2])+ + m[1][2]*(m[2][0]*m[3][1] - m[2][1]*m[3][0])); +} + +double +tracem3(Matrix3 m) +{ + return m[0][0] + m[1][1] + m[2][2] + m[3][3]; +} + +void +adjm3(Matrix3 m) +{ + Matrix3 tmp; + + tmp[0][0]=m[1][1]*(m[2][2]*m[3][3] - m[2][3]*m[3][2])+ + m[2][1]*(m[1][3]*m[3][2] - m[1][2]*m[3][3])+ + m[3][1]*(m[1][2]*m[2][3] - m[1][3]*m[2][2]); + tmp[0][1]=m[0][1]*(m[2][3]*m[3][2] - m[2][2]*m[3][3])+ + m[2][1]*(m[0][2]*m[3][3] - m[0][3]*m[3][2])+ + m[3][1]*(m[0][3]*m[2][2] - m[0][2]*m[2][3]); + tmp[0][2]=m[0][1]*(m[1][2]*m[3][3] - m[1][3]*m[3][2])+ + m[1][1]*(m[0][3]*m[3][2] - m[0][2]*m[3][3])+ + m[3][1]*(m[0][2]*m[1][3] - m[0][3]*m[1][2]); + tmp[0][3]=m[0][1]*(m[1][3]*m[2][2] - m[1][2]*m[2][3])+ + m[1][1]*(m[0][2]*m[2][3] - m[0][3]*m[2][2])+ + m[2][1]*(m[0][3]*m[1][2] - m[0][2]*m[1][3]); + tmp[1][0]=m[1][0]*(m[2][3]*m[3][2] - m[2][2]*m[3][3])+ + m[2][0]*(m[1][2]*m[3][3] - m[1][3]*m[3][2])+ + m[3][0]*(m[1][3]*m[2][2] - m[1][2]*m[2][3]); + tmp[1][1]=m[0][0]*(m[2][2]*m[3][3] - m[2][3]*m[3][2])+ + m[2][0]*(m[0][3]*m[3][2] - m[0][2]*m[3][3])+ + m[3][0]*(m[0][2]*m[2][3] - m[0][3]*m[2][2]); + tmp[1][2]=m[0][0]*(m[1][3]*m[3][2] - m[1][2]*m[3][3])+ + m[1][0]*(m[0][2]*m[3][3] - m[0][3]*m[3][2])+ + m[3][0]*(m[0][3]*m[1][2] - m[0][2]*m[1][3]); + tmp[1][3]=m[0][0]*(m[1][2]*m[2][3] - m[1][3]*m[2][2])+ + m[1][0]*(m[0][3]*m[2][2] - m[0][2]*m[2][3])+ + m[2][0]*(m[0][2]*m[1][3] - m[0][3]*m[1][2]); + tmp[2][0]=m[1][0]*(m[2][1]*m[3][3] - m[2][3]*m[3][1])+ + m[2][0]*(m[1][3]*m[3][1] - m[1][1]*m[3][3])+ + m[3][0]*(m[1][1]*m[2][3] - m[1][3]*m[2][1]); + tmp[2][1]=m[0][0]*(m[2][3]*m[3][1] - m[2][1]*m[3][3])+ + m[2][0]*(m[0][1]*m[3][3] - m[0][3]*m[3][1])+ + m[3][0]*(m[0][3]*m[2][1] - m[0][1]*m[2][3]); + tmp[2][2]=m[0][0]*(m[1][1]*m[3][3] - m[1][3]*m[3][1])+ + m[1][0]*(m[0][3]*m[3][1] - m[0][1]*m[3][3])+ + m[3][0]*(m[0][1]*m[1][3] - m[0][3]*m[1][1]); + tmp[2][3]=m[0][0]*(m[1][3]*m[2][1] - m[1][1]*m[2][3])+ + m[1][0]*(m[0][1]*m[2][3] - m[0][3]*m[2][1])+ + m[2][0]*(m[0][3]*m[1][1] - m[0][1]*m[1][3]); + tmp[3][0]=m[1][0]*(m[2][2]*m[3][1] - m[2][1]*m[3][2])+ + m[2][0]*(m[1][1]*m[3][2] - m[1][2]*m[3][1])+ + m[3][0]*(m[1][2]*m[2][1] - m[1][1]*m[2][2]); + tmp[3][1]=m[0][0]*(m[2][1]*m[3][2] - m[2][2]*m[3][1])+ + m[2][0]*(m[0][2]*m[3][1] - m[0][1]*m[3][2])+ + m[3][0]*(m[0][1]*m[2][2] - m[0][2]*m[2][1]); + tmp[3][2]=m[0][0]*(m[1][2]*m[3][1] - m[1][1]*m[3][2])+ + m[1][0]*(m[0][1]*m[3][2] - m[0][2]*m[3][1])+ + m[3][0]*(m[0][2]*m[1][1] - m[0][1]*m[1][2]); + tmp[3][3]=m[0][0]*(m[1][1]*m[2][2] - m[1][2]*m[2][1])+ + m[1][0]*(m[0][2]*m[2][1] - m[0][1]*m[2][2])+ + m[2][0]*(m[0][1]*m[1][2] - m[0][2]*m[1][1]); + memmove(m, tmp, 4*4*sizeof(double)); +} + +void +invertm3(Matrix3 m) +{ + Matrix3 m², m³, r; + double det, trm, trm², trm³; + + det = detm3(m); + if(det == 0) + return; /* singular matrices are not invertible */ + trm = tracem3(m); + memmove(m³, m, 4*4*sizeof(double)); + mulm3(m³, m³); + mulm3(m³, m); + trm³ = tracem3(m³); + memmove(m², m, 4*4*sizeof(double)); + mulm3(m², m²); + trm² = tracem3(m²); + identity3(r); + smulm3(r, (trm*trm*trm - 3*trm*trm² + 2*trm³)/6); + smulm3(m, (trm*trm - trm²)/2); + smulm3(m², trm); + subm3(r, m); + addm3(r, m²); + subm3(r, m³); + smulm3(r, 1/det); + memmove(m, r, 4*4*sizeof(double)); +} + +void +cinvertm3(Matrix3 m) +{ + double det; + + det = detm3(m); + if(det == 0) + return; /* singular matrices are not invertible */ + adjm3(m); + smulm3(m, 1/det); +} + +void +printm(Matrix m) +{ + int i, j; + + for(i = 0; i < 3; i++){ + for(j = 0; j < 3; j++) + print("\t%g", m[i][j]); + print("\n"); + } +} + +void +printm3(Matrix3 m) +{ + int i, j; + + for(i = 0; i < 4; i++){ + for(j = 0; j < 4; j++) + print("\t%g", m[i][j]); + print("\n"); + } +} + +vlong t0, t; + +void +main() +{ + Matrix m = { + // 7, 2, 1, + // 0, 3, -1, + // -3, 4, -2 + /* near-singular */ + 1, 1, 1, + 0, 1, 0, + 1, 0, 1.01 + }, invm, cinvm; + Matrix3 M = { + 1, 1, 1, -1, + 1, 1, -1, 1, + 1, -1, 1, 1, + -1, 1, 1, 1 + }, invM, cinvM; + + memmove(invm, m, 3*3*sizeof(double)); + memmove(cinvm, m, 3*3*sizeof(double)); + print("M:\n"); + printm(m); + t0 = nsec(); + invertm(invm); + t = nsec()-t0; + print("M⁻¹(%lldns):\n", t); + printm(invm); + t0 = nsec(); + cinvertm(cinvm); + t = nsec()-t0; + print("CM⁻¹(%lldns):\n", t); + printm(cinvm); + mulm(m, invm); + print("MM⁻¹:\n"); + printm(m); + memmove(invM, M, 4*4*sizeof(double)); + memmove(cinvM, M, 4*4*sizeof(double)); + print("M:\n"); + printm3(M); + t0 = nsec(); + invertm3(invM); + t = nsec()-t0; + print("M⁻¹(%lldns):\n", t); + printm3(invM); + t0 = nsec(); + cinvertm3(cinvM); + t = nsec()-t0; + print("CM⁻¹(%lldns):\n", t); + printm3(cinvM); + mulm3(M, invM); + print("MM⁻¹:\n"); + printm3(M); + exits(nil); +} diff --git a/matrixmul.c b/matrixmul.c new file mode 100644 index 0000000..c2da272 --- /dev/null +++ b/matrixmul.c @@ -0,0 +1,53 @@ +#include <u.h> +#include <libc.h> + +typedef double Matrix[4][4]; + +void +mulm(Matrix a, Matrix b) +{ + int i, j, k; + Matrix r; + + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++){ + r[i][j] = 0; + for(k = 0; k < 4; k++) + r[i][j] += a[i][k]*b[k][j]; + } + for(i = 0; i < 4; i++) + for(j = 0; j < 4; j++) + a[i][j] = r[i][j]; +} + +void +printm(Matrix m) +{ + int i, j; + + for(i = 0; i < 4; i++){ + for(j = 0; j < 4; j++) + print("%g\t", m[i][j]); + print("\n"); + } +} + +void +main() +{ + Matrix m1 = { + 1, 2, -1, 0, + 2, 0, 1, 0, + 0, 0, 0, 0, + 0, 0, 0, 0 + }; + Matrix m2 = { + 3, 1, 0, 0, + 0, -1, 0, 0, + -2, 3, 0, 0, + 0, 0, 0, 0 + }; + mulm(m1, m2); + printm(m1); + exits(0); +} diff --git a/minhello.c b/minhello.c new file mode 100644 index 0000000..873bc09 --- /dev/null +++ b/minhello.c @@ -0,0 +1,9 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + write(1, "Hello world\n", 12); + exits(0); +} diff --git a/multibatt.c b/multibatt.c new file mode 100644 index 0000000..48d27c4 --- /dev/null +++ b/multibatt.c @@ -0,0 +1,30 @@ +#include <u.h> +#include <libc.h> + +char f[] = "/mnt/acpi/battery"; +char buf[512]; +char *s; +int nb = 0; + +void +main(void) +{ + int fd; + + fd = open(f, OREAD); + if(fd < 0) + sysfatal("open: %r"); + + read(fd, buf, sizeof buf); + + buf[strlen(buf)-1] = '\0'; + + print("%d\n", atoi(buf)); nb++; + for(s = buf; *s != '\0'; s++) + if(*s == '\n'){ + nb++; + print("%d\n", atoi(++s)); + } + print("batteries: %d\n", nb); + exits("done"); +} diff --git a/nhello.c b/nhello.c new file mode 100644 index 0000000..83f07b1 --- /dev/null +++ b/nhello.c @@ -0,0 +1,15 @@ +#include <u.h> +#include <libc.h> + +char c; +int n; + +void +main() +{ + read(0, &c, 1); + n = c-'0'; + while(n-- > 0) + write(1, "Hola mundo.\n", 12); + exits(0); +} diff --git a/nonrecurfact.c b/nonrecurfact.c new file mode 100644 index 0000000..3fdbf78 --- /dev/null +++ b/nonrecurfact.c @@ -0,0 +1,58 @@ +/* non-recursive factorial */ +#include <u.h> +#include <libc.h> + +void +printdec(int n) +{ + char s[16], *p; + int r; + + p = s+16; + *--p = '\n'; + for(;;){ + r = n%10; + *--p = '0'+r; + n /= 10; + if(n == 0 || p == s) + break; + } + write(1, p, s+sizeof(s)-p); +} + +int +fact(int n) +{ + int a; + + a = n; +repeat: + if(n <= 0) + return 0; + else if(n == 1) + return a; + a *= --n; + goto repeat; +} + +void +usage(void) +{ + fprint(2, "usage: %s n\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int n; + + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc != 1) + usage(); + n = strtol(argv[0], nil, 0); + printdec(fact(n)); + exits(0); +} @@ -0,0 +1,14 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char s[] = ",."; + char *p; + + p = s; + while(*p++ == '.' || *p == '.') + print("dot"); + exits(0); +} @@ -0,0 +1,15 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + int n; + int *p; + + n = 4; + p = &n; + print("%d\n", ++*p); + print("%d\n", n); + exits(0); +} diff --git a/printdec.c b/printdec.c new file mode 100644 index 0000000..c061c22 --- /dev/null +++ b/printdec.c @@ -0,0 +1,60 @@ +#include <u.h> +#include <libc.h> + +void +swap(char *a, char *b) +{ + char tmp; + + tmp = *a; + *a = *b; + *b = tmp; +} + +void +srev(char *s, char *e) +{ + while(s < e) + swap(s++, e--); +} + +void +printdec(int n) +{ + char buf[16]; + char *p, *e; + int r; + + p = buf; + e = buf+sizeof(buf)-1; + while(n > 0 && p < e){ + r = n%10; + *p++ = '0'+r; + n /= 10; + } + *p = 0; + print("%s\n", buf); +} + +void +usage(void) +{ + fprint(2, "usage: %s number\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int n; + + ARGBEGIN{ + default: usage(); + }ARGEND + if(argc != 1) + usage(); + srev(argv[0], argv[0]+strlen(argv[0])-1); + n = strtol(argv[0], nil, 10); + printdec(n); + exits(0); +} @@ -0,0 +1,94 @@ +#include <u.h> +#include <libc.h> + +#define DEG 0.01745329251994330 + +typedef struct Quaternion Quaternion; +struct Quaternion { + double r, i, j, k; +}; +typedef struct Point3 Point3; +struct Point3 { + double x, y, z, w; +}; + +Point3 +Vec3(double x, double y, double z) +{ + return (Point3){x, y, z, 0}; +} + +Point3 +addpt3(Point3 a, Point3 b) +{ + return (Point3){a.x+b.x, a.y+b.y, a.z+b.z, a.w+b.w}; +} + +Point3 +mulpt3(Point3 p, double s) +{ + return (Point3){p.x*s, p.y*s, p.z*s, p.w*s}; +} + +double +dotvec3(Point3 a, Point3 b) +{ + return a.x*b.x + a.y*b.y + a.z*b.z; +} + +Point3 +crossvec3(Point3 a, Point3 b) +{ + return (Point3){ + a.y*b.z - a.z*b.y, + a.z*b.x - a.x*b.z, + a.x*b.y - a.y*b.x, + 0 + }; +} + +Quaternion +mulq(Quaternion q, Quaternion r) +{ + Point3 qv, rv, tmp; + + qv = Vec3(q.i, q.j, q.k); + rv = Vec3(r.i, r.j, r.k); + tmp = addpt3(addpt3(mulpt3(rv, q.r), mulpt3(qv, r.r)), crossvec3(qv, rv)); + return (Quaternion){q.r*r.r - dotvec3(qv, rv), tmp.x, tmp.y, tmp.z}; +} + +Quaternion +invq(Quaternion q) +{ + double len²; + + len² = q.r*q.r + q.i*q.i + q.j*q.j + q.k*q.k; + if(len² == 0) + return (Quaternion){0, 0, 0, 0}; + return (Quaternion){q.r/len², -q.i/len², -q.j/len², -q.k/len²}; +} + +#pragma varargck type "q" Quaternion +int +qfmt(Fmt *f) +{ + Quaternion q; + + q = va_arg(f->args, Quaternion); + return fmtprint(f, "[%g %g %g %g]", q.r, q.i, q.j, q.k); +} + +void +main() +{ + Quaternion q; + double c, s; + + fmtinstall('q', qfmt); + c = cos(45*DEG); + s = sin(45*DEG); + q = (Quaternion){c, s, s, s}; + print("q %q\nq⁻¹ %q\nqq⁻¹ %q\n", q, invq(q), mulq(q, invq(q))); + exits(nil); +} @@ -0,0 +1,70 @@ +#include <u.h> +#include <libc.h> + +typedef struct Node Node; +struct Node { + int n; + Node *next; +}; + +Node *head, *tail; + +void * +emalloc(ulong n) +{ + void *p; + + p = malloc(n); + if(p == nil) + sysfatal("malloc: %r"); + memset(p, 0, n); + setmalloctag(p, getcallerpc(&n)); + return p; +} + +void +put(int n) +{ + if(tail == nil){ + tail = emalloc(sizeof(Node)); + tail->n = n; + head = tail; + return; + } + tail->next = emalloc(sizeof(Node)); + tail = tail->next; + tail->n = n; +} + +int +get(void) +{ + Node *nn; + int n; + + if(head == nil) + return -1; + nn = head->next; + n = head->n; + free(head); + head = nn; + return n; +} + +int +isemtpy(void) +{ + return head == nil; +} + +void +main() +{ + int i; + + for(i = 0; i < 10; i++) + put(i*3); + while(!isemtpy()) + print("%d\n", get()); + exits(nil); +} @@ -0,0 +1,19 @@ +#include <u.h> +#include <libc.h> + +int +ret(void) +{ + if(2 > 3) + return 2; + else + exits("error"); + return -1; +} + +void +main() +{ + ret(); + exits(0); +} @@ -0,0 +1,48 @@ +#include <u.h> +#include <libc.h> + +void +swap(char *a, char *b) +{ + char tmp; + + tmp = *a; + *a = *b; + *b = tmp; +} + +void +rev(char *s, ulong len) +{ + char *e; + + e = s+len; + while(s < e) + swap(s++, --e); +} + +void +usage(void) +{ + fprint(2, "usage: %s text ...\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + int first; + + first = 1; + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc < 1) + usage(); + while(argc--){ + rev(argv[argc], strlen(argv[argc])); + print(first ? first--, "%s" : " %s", argv[argc]); + } + print("\n"); + exits(nil); +} diff --git a/revdonewrong.c b/revdonewrong.c new file mode 100644 index 0000000..d6bb631 --- /dev/null +++ b/revdonewrong.c @@ -0,0 +1,42 @@ +#include <u.h> +#include <libc.h> + +void +swap(char *a, char *b) +{ + char tmp; + + tmp = *a; + *a = *b; + *b = tmp; +} + +void +rev(char *s, ulong len) +{ + char *e; + + e = s+len; + while(s != e) + swap(s++, --e); +} + +void +usage(void) +{ + fprint(2, "usage: %s text\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc != 1) + usage(); + rev(argv[0], strlen(argv[0])); + print("%s\n", argv[0]); + exits(nil); +} diff --git a/reverse.c b/reverse.c new file mode 100644 index 0000000..a038df2 --- /dev/null +++ b/reverse.c @@ -0,0 +1,42 @@ +#include <u.h> +#include <libc.h> + +char * +reverse(char *s, int n) +{ + int i; + char tmp; + + for(i = 0; i < n/2; i++){ + tmp = s[i]; + s[i] = s[n-i-1]; + s[n-i-1] = tmp; + } + return s; +} + +char * +reversep(char *s, int n) +{ + char *bp, *ep; + char tmp; + + for(bp = s, ep = s+n-1; bp != ep; bp++, ep--){ + tmp = *bp; + *bp = *ep; + *ep = tmp; + } + return s; +} + +void +main() +{ + char s[] = "hello"; + + print("%s → ", s); + print("%s\n", reverse(s, strlen(s))); + print("%s → ", s); + print("%s\n", reversep(s, strlen(s))); + exits(0); +} diff --git a/rounding.c b/rounding.c new file mode 100644 index 0000000..db78664 --- /dev/null +++ b/rounding.c @@ -0,0 +1,37 @@ +#include <u.h> +#include <libc.h> + +double +roundf(double n) +{ + return floor(n + 0.5); +} + +int +roundi(double n) +{ + return n+0.5; +} + +void +usage(void) +{ + fprint(2, "usage: %s number\n", argv0); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + double n; + + ARGBEGIN{ + default: usage(); + }ARGEND; + if(argc != 1) + usage(); + n = strtod(argv[0], nil); + print("%g\n", roundf(n)); + print("%d\n", roundi(n)); + exits(0); +} @@ -0,0 +1,51 @@ +#include <u.h> +#include <libc.h> +#include <ctype.h> +#include <bio.h> + +int stk[256], sp; +Biobuf *bin; + +void +push(int n) +{ + if(sp >= sizeof stk) + sp = sizeof(stk)-1; + fprint(2, "push [%d] %d\n", sp, n); + stk[sp++] = n; +} + +int +pop(void) +{ + if(sp <= 0) + sp = 1; + fprint(2, "pop [%d] %d\n", sp-1, stk[sp-1]); + return stk[--sp]; +} + +void +main() +{ + int x; + char c; + + bin = Bfdopen(0, OREAD); + if(bin == nil) + sysfatal("Bfdopen: %r"); + while((c = Bgetc(bin)) != Beof){ + x = 0; + switch(c){ + case '+': x = pop() + pop(); break; + case '*': x = pop() * pop(); break; + default: + while(isdigit(c)){ + x = x*10 + c-'0'; + c = Bgetc(bin); + } + } + push(x); + } + print("%d\n", pop()); + exits(nil); +} diff --git a/seeking.c b/seeking.c new file mode 100644 index 0000000..c2f00ed --- /dev/null +++ b/seeking.c @@ -0,0 +1,24 @@ +#include <u.h> +#include <libc.h> + +#define MAXREADS 3 + +void +main(void) +{ + int fd, i; + char buf[4]; + + fd = open("/mnt/acpi/battery", OREAD); + if(fd < 0) + sysfatal("couldn't open it"); + + for(i = 0; i < MAXREADS; i++){ + pread(fd, buf, sizeof buf, 0); + buf[sizeof(buf)-1] = '\0'; + print(buf); + } + + close(fd); + exits("done"); +} diff --git a/signed.c b/signed.c new file mode 100644 index 0000000..050b66f --- /dev/null +++ b/signed.c @@ -0,0 +1,14 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + int x; + + x = 25; + print("n:%d,s:%d\n", x, (x>>31)); + x *= -1; + print("n:%d,s:%d\n", x, (x>>31)); + exits(0); +} diff --git a/sizeof2d.c b/sizeof2d.c new file mode 100644 index 0000000..29bd530 --- /dev/null +++ b/sizeof2d.c @@ -0,0 +1,11 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char m[10][5]; + + print("%d\n", sizeof(m)); + exits(nil); +} diff --git a/smiley.pic b/smiley.pic new file mode 100644 index 0000000..611228d --- /dev/null +++ b/smiley.pic @@ -0,0 +1,26 @@ +.PS +define smiley { + # takes three arguments: x, y and size (radius) + + r0 = $3 # Face + r1 = 0.4*r0 # Radius of mouth and eye locations + r2 = 0.04*r0 # Radius of eyes + +C: circle rad r0 at ( $1, $2 ) + + circle rad r2 filled at last circle + ( r1, r1 ) # Right eye + circle rad r2 filled at 2nd last circle + ( -r1, r1 ) # Left eye + + pi = atan2( 0, -1 ) +S: C + ( r1 * cos(1.25*pi), r1 * sin(1.25*pi) ) + line from S to S + for phi=1.25*pi to 1.75*pi by 0.1 do { + line to C + ( r1 * cos(phi), r1 * sin(phi) ) # Mouth + } +} + +pi2 = 2 * atan2( 0, -1 ) +for x=0.1 to 1.3 by 0.08 do { + smiley( 1.5 * x * cos(x*pi2), 1.1 * x * sin(x*pi2), 0.23 * x ) +} +.PE diff --git a/snprintandf.c b/snprintandf.c new file mode 100644 index 0000000..17707a2 --- /dev/null +++ b/snprintandf.c @@ -0,0 +1,18 @@ +#include <u.h> +#include <libc.h> +#include <stdio.h> + +void +main() +{ + char *s; + int l; + + s = malloc(128); + l = snprint(s, 128, "%s%s", "hi", "there"); + print("%s(%d)\n", s, l); + l = snprintf(s, 128, "%s%s", "hi", "there"); + print("%s(%d)\n", s, l); + free(s); + exits(0); +} diff --git a/snprinting.c b/snprinting.c new file mode 100644 index 0000000..b0a7095 --- /dev/null +++ b/snprinting.c @@ -0,0 +1,13 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char buf[128]; + int n; + + n = snprint(buf, sizeof buf, "%s:%d\n", "actual.out", 2); + print("%d\n", n); + exits(0); +} diff --git a/spranimate.c b/spranimate.c new file mode 100644 index 0000000..347be3c --- /dev/null +++ b/spranimate.c @@ -0,0 +1,98 @@ +#include <u.h> +#include <libc.h> +#include <draw.h> + +enum { SEC = 1000 }; + +enum { + Cred, + Cgrn, + + Cbg, + + Cgx, + Cend +}; +Image *col[Cend]; + +int dx, dy; + +void * +emalloc(ulong n) +{ + void *p; + + p = malloc(n); + if(p == nil) + sysfatal("malloc: %r"); + memset(p, 0, n); + setmalloctag(p, getcallerpc(&n)); + return p; +} + +Image * +eallocimage(Display *d, Rectangle r, ulong chan, int repl, ulong col) +{ + Image *i; + + i = allocimage(d, r, chan, repl, col); + if(i == nil) + sysfatal("allocimage: %r"); + return i; +} + +void +usage(void) +{ + fprint(2, "usage: spranimate\n"); + exits("usage"); +} + +void +main(int argc, char *argv[]) +{ + Image *spnr, *spnmsk; + double θ; + uchar *gx; + int ds, i, x, y, inc, frame; + + ARGBEGIN{ + default: usage(); + }ARGEND; + + if(initdraw(nil, nil, "spranimate") < 0) + sysfatal("initdraw: %r"); + dx = Dx(screen->r), dy = Dy(screen->r); + col[Cred] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DRed); + col[Cgrn] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DGreen); + col[Cbg] = eallocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DNofill); + ds = dx > dy ? dy : dx; + spnr = eallocimage(display, Rect(0, 0, ds*60, ds), RGBA32, 0, DTransparent); + spnmsk = eallocimage(display, Rect(0, 0, ds, ds), GREY1, 0, DWhite); + col[Cgx] = eallocimage(display, Rect(0, 0, 60, 1), GREY8, 1, DNofill); + gx = emalloc(60); + for(i = 0; i < 60; i++) + gx[i] = 255.0 * i/(60-1); + for(i = 0; i < 60; i++){ + θ = 2*PI * i/60; + x = (ds/2 - 5) * cos(θ); + y = (ds/2 - 5) * sin(θ); + line(spnr, Pt(x + ds/2 + ds*i, y + ds/2), Pt(-x + ds/2 + ds*i, -y + ds/2), Endarrow, Endsquare, 1, display->black, ZP); + } + loadimage(col[Cgx], col[Cgx]->r, gx, dx); + x = inc = frame = 0; + for(;;){ + draw(col[Cbg], col[Cbg]->r, col[Cred], nil, ZP); + if(x == 0) + inc = 1; + else if(x == 60-1) + inc = -1; + x += inc; + gendraw(col[Cbg], col[Cbg]->r, col[Cgrn], ZP, col[Cgx], Pt(x, 0)); + draw(screen, screen->r, col[Cbg], nil, ZP); + frame = (frame+1) % 60; + gendraw(screen, screen->r, spnr, Pt(frame*ds, 0), spnmsk, ZP); + flushimage(display, 1); + sleep(SEC/60); + } +} diff --git a/strlen.c b/strlen.c new file mode 100644 index 0000000..efc063f --- /dev/null +++ b/strlen.c @@ -0,0 +1,11 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char txt[] = "i'm here now\n"; + + print("len: %ld, lastchar: %c\n", strlen(txt), txt[strlen(txt)-1]); + exits(nil); +} diff --git a/structcmp.c b/structcmp.c new file mode 100644 index 0000000..c1f28c1 --- /dev/null +++ b/structcmp.c @@ -0,0 +1,32 @@ +#include <u.h> +#include <libc.h> + +enum { + A = 1, + B = 2, + C = 4, + D = 8 +}; + +typedef struct Fruit Fruit; +struct Fruit { + char *name; + int vitamins; +}; + +void +main() +{ + Fruit apple, lemon, apple2; + + apple = (Fruit){"apple", C}; + lemon = (Fruit){"lemon", B|C}; + apple2 = (Fruit){"apple", C}; + if(apple == apple) + fprint(2, "apple equals apple\n"); + if(apple == apple2) + fprint(2, "apple equals apple2\n"); + if(apple == lemon) + fprint(2, "apple equals lemon, really?\n"); + exits(0); +} diff --git a/structvsarray.c b/structvsarray.c new file mode 100644 index 0000000..2f2ddaa --- /dev/null +++ b/structvsarray.c @@ -0,0 +1,61 @@ +#include <u.h> +#include <libc.h> + +enum { + Ts, + Tp, + Ta, + Tend +}; + +typedef struct Vec Vec; +struct Vec { + double x, y, z; +}; + +typedef double Veca[3]; + +vlong t[Tend], t0; + +Vec +addvec(Vec a, Vec b) +{ + return (Vec){a.x+b.x, a.y+b.y, a.z+b.z}; +} + +void +addvecp(Vec *a, Vec *b) +{ + a->x += b->x; + a->y += b->y; + a->z += b->z; +} + +void +addveca(Veca a, Veca b) +{ + a[0] += b[0]; + a[1] += b[1]; + a[2] += b[2]; +} + +void +main() +{ + Vec a = {5, 2, 19}; + Vec b = {213, 30, -12}; + Veca aa = {2, 9, -1}; + Veca ab = {-10, 20, 30}; + + t0 = nsec(); + a = addvec(a, b); + t[Ts] = nsec()-t0; + t0 = nsec(); + addvecp(&a, &b); + t[Tp] = nsec()-t0; + t0 = nsec(); + addveca(aa, ab); + t[Ta] = nsec()-t0; + print("struct\t%lldns\nstruct*\t%lldns\narray\t%lldns\n", t[Ts], t[Tp], t[Ta]); + exits(nil); +} @@ -0,0 +1,4 @@ +TEXT sum(SB), $0 + MOVL b+8(FP), AX + ADDL BP, AX + RET diff --git a/sumain.c b/sumain.c new file mode 100644 index 0000000..8db2ab2 --- /dev/null +++ b/sumain.c @@ -0,0 +1,14 @@ +#include <u.h> +#include <libc.h> + +int sum(int, int); + +void +main() +{ + int n; + + n = sum(24, 30); + print("Σ = %d\n", n); + exits(nil); +} @@ -0,0 +1,48 @@ +#include <u.h> +#include <libc.h> +#include <draw.h> +#include <thread.h> + +Channel *spamchan; + +void +freethread(void *) +{ + char *v = nil; + + threadsetname("freethread"); +Loop: + recv(spamchan, &v); + if(v == nil){ + print("nothing to free\n"); + threadexitsall(0); + } + print("freeing %s\n", v); + free(v); + goto Loop; +} + +void +spammer(void*) +{ + int i; + char *s; + + threadsetname("spammer"); + for(i = 0; i < 10; ++i){ + s = smprint("%d", i); + send(spamchan, &s); + } + send(spamchan, nil); +} + +void +threadmain(int argc, char *argv[]) +{ + print("acid -l thread %d\n", getpid()); + threadsetname("main"); + spamchan = chancreate(sizeof(char*), 0); + threadcreate(spammer, nil, 8192); + threadcreate(freethread, nil, 8192); + yield(); +} @@ -0,0 +1,14 @@ +#include <u.h> +#include <libc.h> + +void +greet(void) +{ + write(1, "hello world\n", 12); +} + +void +main() +{ + greet(); +} @@ -0,0 +1,16 @@ +#include <u.h> +#include <libc.h> + +void +main() +{ + char buf[256], *f[10]; + int nf, i; + + while(read(0, buf, sizeof(buf)-1) > 0){ + nf = tokenize(buf, f, nelem(f)); + for(i = 0; i < nf; i++) + fprint(2, "%d: %s\n", i, f[i]); + } + exits(0); +} diff --git a/transpose.c b/transpose.c new file mode 100644 index 0000000..ee607f6 --- /dev/null +++ b/transpose.c @@ -0,0 +1,49 @@ +#include <u.h> +#include <libc.h> + +#define N 4 + +typedef double Matrix[N][N]; + +void +transpose(Matrix a) +{ + int i, j; + double tmp; + + for(i = 0; i < N; i++) + for(j = i; j < N; j++){ + tmp = a[i][j]; + a[i][j] = a[j][i]; + a[j][i] = tmp; + } +} + +void +printm(Matrix m) +{ + int i, j; + + for(i = 0; i < N; i++){ + for(j = 0; j < N; j++) + print("%g ", m[i][j]); + print("\n"); + } + print("\n"); +} + +void +main() +{ + Matrix m = { + 11, 12, 13, 14, + 21, 22, 23, 24, + 31, 32, 33, 34, + 41, 42, 43, 44, + }; + + printm(m); + transpose(m); + printm(m); + exits(0); +} @@ -0,0 +1,26 @@ +#include <u.h> +#include <libc.h> + +typedef struct Vec Vec; +struct Vec { + double x, y, z; +}; + +Vec +addvec(Vec a, Vec b) +{ + a.x += b.x; + a.y += b.y; + a.z += b.z; + return a; +} + +void +main() +{ + Vec a = {20, 5, 3}; + Vec b = {6, -2, 19}; + + a = addvec(a, b); + exits(nil); +} |