diff options
Diffstat (limited to 'src/lib9/flag.c')
| -rw-r--r-- | src/lib9/flag.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/src/lib9/flag.c b/src/lib9/flag.c new file mode 100644 index 000000000..7c79c1a6d --- /dev/null +++ b/src/lib9/flag.c @@ -0,0 +1,307 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include <u.h> +#include <libc.h> + +// Flag hash. +typedef struct Flag Flag; + +struct Flag +{ + char *name; + int namelen; + char *desc; + int iscount; + void (*set)(char*, void*); + void (*set2)(char*, char*, void*); + void *arg; + Flag *next; + Flag *allnext; +}; + +static Flag *curflag; + +static Flag *fhash[512]; +static Flag *first, *last; + +char *argv0; + +/* + * Mac OS can't deal with files that only declare data. + * ARGBEGIN mentions this function so that this file gets pulled in. + */ +void __fixargv0(void) { } + +// FNV-1 hash. http://isthe.com/chongo/tech/comp/fnv/ +static uint32 +fnv(char *p, int n) +{ + uint32 h; + + h = 2166136261U; + while(n-- > 0) + h = (h*16777619) ^ (uchar)*p++; + return h; +} + +static Flag* +lookflag(char *name, int namelen, int creat) +{ + uint32 h; + Flag *f; + + h = fnv(name, namelen) & (nelem(fhash)-1); + for(f=fhash[h]; f; f=f->next) { + if(f->namelen == namelen && memcmp(f->name, name, namelen) == 0) { + if(creat) + sysfatal("multiple definitions of flag -%s", name); + return f; + } + } + + if(!creat) + return nil; + + f = malloc(sizeof *f); + if(f == nil) + sysfatal("out of memory"); + memset(f, 0, sizeof *f); + f->name = name; + f->namelen = namelen; + f->next = fhash[h]; + if(first == nil) + first = f; + else + last->allnext = f; + last = f; + fhash[h] = f; + return f; +} + +static void +count(char *arg, void *p) +{ + int *ip; + + ip = p; + if(arg != nil) + *ip = atoi(arg); + else + (*ip)++; +} + +void +flagcount(char *name, char *desc, int *p) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->iscount = 1; + f->set = count; + f->arg = p; +} + +static void +atollwhex(char *s, void *p) +{ + char *t; + + *(int64*)p = strtoll(s, &t, 0); + if(*s == '\0' || *t != '\0') + sysfatal("invalid numeric argument -%s=%s", curflag->name, s); +} + +void +flagint64(char *name, char *desc, int64 *p) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set = atollwhex; + f->arg = p; +} + +static void +atolwhex(char *s, void *p) +{ + char *t; + + *(int32*)p = strtol(s, &t, 0); + if(*s == '\0' || *t != '\0') + sysfatal("invalid numeric argument -%s=%s", curflag->name, s); +} + +void +flagint32(char *name, char *desc, int32 *p) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set = atolwhex; + f->arg = p; +} + +static void +string(char *s, void *p) +{ + *(char**)p = s; +} + +void +flagstr(char *name, char *desc, char **p) +{ + + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set = string; + f->arg = p; +} + +static void +fn0(char *s, void *p) +{ + USED(s); + ((void(*)(void))p)(); +} + +void +flagfn0(char *name, char *desc, void (*fn)(void)) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set = fn0; + f->arg = fn; + f->iscount = 1; +} + +static void +fn1(char *s, void *p) +{ + ((void(*)(char*))p)(s); +} + +void +flagfn1(char *name, char *desc, void (*fn)(char*)) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set = fn1; + f->arg = fn; +} + +static void +fn2(char *s, char *t, void *p) +{ + ((void(*)(char*, char*))p)(s, t); +} + +void +flagfn2(char *name, char *desc, void (*fn)(char*, char*)) +{ + Flag *f; + + f = lookflag(name, strlen(name), 1); + f->desc = desc; + f->set2 = fn2; + f->arg = fn; +} + +void +flagparse(int *argcp, char ***argvp, void (*usage)(void)) +{ + int argc; + char **argv, *p, *q; + char *name; + int namelen; + Flag *f; + + argc = *argcp; + argv = *argvp; + + argv0 = argv[0]; + argc--; + argv++; + + while(argc > 0) { + p = *argv; + // stop before non-flag or - + if(*p != '-' || p[1] == '\0') + break; + argc--; + argv++; + // stop after -- + if(p[1] == '-' && p[2] == '\0') { + break; + } + + // turn --foo into -foo + if(p[1] == '-' && p[2] != '-') + p++; + + // allow -flag=arg if present + name = p+1; + q = strchr(name, '='); + if(q != nil) + namelen = q++ - name; + else + namelen = strlen(name); + f = lookflag(name, namelen, 0); + if(f == nil) { + if(strcmp(p, "-h") == 0 || strcmp(p, "-help") == 0 || strcmp(p, "-?") == 0) + usage(); + sysfatal("unknown flag %s", p); + } + curflag = f; + + // otherwise consume next argument if non-boolean + if(!f->iscount && q == nil) { + if(argc-- == 0) + sysfatal("missing argument to flag %s", p); + q = *argv++; + } + + // and another if we need two + if(f->set2 != nil) { + if(argc-- == 0) + sysfatal("missing second argument to flag %s", p); + f->set2(q, *argv++, f->arg); + continue; + } + + f->set(q, f->arg); + } + + *argcp = argc; + *argvp = argv; +} + +void +flagprint(int fd) +{ + Flag *f; + char *p, *q; + + for(f=first; f; f=f->allnext) { + p = f->desc; + if(p == nil || *p == '\0') // undocumented flag + continue; + q = strstr(p, ": "); + if(q) + fprint(fd, " -%s %.*s\n \t%s\n", f->name, utfnlen(p, q-p), p, q+2); + else if(f->namelen > 1) + fprint(fd, " -%s\n \t%s\n", f->name, p); + else + fprint(fd, " -%s\t%s\n", f->name, p); + } +} |