[unix-history] / usr / src / usr.bin / f77 / libI77 / util.c

/*
char id_util[] = "@(#)util.c    1.6";
*
* utility routines
*/

#include <sys/types.h>
#include <sys/stat.h>
#include "fio.h"

extern short    ccntrl_, blzero_;

ini_std(u,F,w) FILE *F;
{       unit *p;
       p = &units[u];
       p->ufd = F;
       p->ufnm = NULL;
       p->useek = canseek(F);
       p->ufmt = YES;
       p->uwrt = (w==WRITE)? YES : NO;
       p->uscrtch = p->uend = NO;
       p->ublnk = blzero_;
       p->uprnt = ccntrl_;
       p->url = 0;
       p->uinode = finode(F);
}

canseek(f) FILE *f; /*SYSDEP*/
{       struct stat x;
       return( (fstat(fileno(f),&x)==0) &&
       (x.st_nlink > 0 /*!pipe*/) && !isatty(fileno(f)) );
}

nowreading(x) unit *x;
{
       return(now_acc(x,"r"));
}

nowwriting(x) unit *x;
{
       return(now_acc(x,"a"));
}

now_acc(x,mode)
unit *x; char *mode;
{
       long loc;

       if (!x->ufnm)
       {
               errno = EBADF;
               return(NO);
       }
       if (x->useek)
               loc=ftell(x->ufd);
       if (freopen(x->ufnm,mode,x->ufd))
       {
               if (x->useek)
                       fseek(x->ufd,loc,0);
               x->uwrt = (*mode=='a');
               return(YES);
       }
       if (x->ufd = fopen(x->ufnm, (*mode=='a')? "r":"a"))
               if (x->useek)
                       fseek(x->ufd,loc,0);
       return(NO);
}

g_char(a,alen,b) char *a,*b; ftnlen alen;
{       char *x=a+alen-1, *y=b+alen-1;
       while (x >= a  &&  *x == ' ') {x--; y--;}
       *(y+1) = '\0';
       while (x >= a) *y-- = *x--;
}

b_char(from, to, tolen) char *from, *to; ftnlen tolen;
{       int i=0;
       while (*from && i < tolen) {
               *to++ = *from++;
               i++;
       }
       while (i++ < tolen)
               *to++ = ' ';
}

inode(a) char *a;
{       struct stat x;
       if(stat(a,&x)==0) return(x.st_ino);
       else return(-1);
}

finode(f) FILE *f;
{       struct stat x;
       if(fstat(fileno(f),&x)==0) return(x.st_ino);
       else return(-1);
}

char
last_char(f) FILE *f;
{
       fseek(f,-2L,1);
       if(ftell(f)) return(getc(f));
       else return('\n');
}