BSD 3 development

[unix-history] / usr / src / cmd / sdb / fio.c

#include "head.h"

/*
* These procedures manage the source files examined by sdb.
*/

/* Change the current source file to `name'. */
finit(name)
char *name; {
       register char *p, *q;
       
       if (fiobuf.fd) close(fiobuf.fd);
       q = name;
       for (p=fp; *q; *p++ = *q++) ;
       *p = 0;
       if ((fiobuf.fd = open(filework,0)) == -1) {
               nolines = 1;
               perror(filework);
               return;
       }
       binit(&fiobuf);
       cpstr(curfile, name);
       for (p=fbuf;;p++) {
               if (bread(&fiobuf,p,1) <= 0) {
                       nolines = 1;
                       printf("%s: No lines in file\n", name);
                       return;
               }
               if (*p == '\n') break;
       }
       fline = 1;
       maxfline = 0;
       nolines = 0;
}

/* Make the next line current. */
fnext() {
       register char *p;
       
       if (nolines){
               return;
       }
       for(p=fbuf;;p++) {
               if (bread(&fiobuf,p,1) <= 0) {
                       p--;
                       blseek(&fiobuf,0L,0);
                       fline = 0;
                       continue;
               }
               if (*p == '\n') break;
       }
       fline++;
}


/* Make the previous line current. */
fprev() {
       char c;
       register int i;
       
       if (nolines){
               return;
       }
       for(i=0; i<3; i++) {
               for (;;) {
                       if (bread(&fiobuf, &c+1, -1) <= 0) {
                               if (maxfline) blseek(&fiobuf,0L,2);
                               else {
                                       blseek(&fiobuf,0L,0);
                                       for(;;) {
                                               if (bread(&fiobuf,&c,1)<=0)
                                                       break;
                                               if (c == '\n') maxfline++;
                                       }
                               }
                       }
                       if (c == '\n') break;
               }
       }
       bread(&fiobuf, &c, 1);  /* eat the '\n' */
       
       fline -= 2;
       if (fline < 0) fline = maxfline - 1;
       
       fnext();
}


/* Print the current line. */
fprint() {
       register char *p;
       
       if (nolines){
               error("No lines in file");
               return;
       }
       printf("%d: ", fline);
       p = fbuf;
       while(putchar(*p++) != '\n')
               ;
}

/* Make line `num' current. */
ffind(num)
register int num; {
       register int i, ofline;
       
       if (nolines){
               return;
       }
       ofline = fline;
       if (num>fline)
               for (i=fline; i<num; i++) {
                       fnext();
                       if (fline == 1) goto bad;
               }
       if (num<fline)
               for (i=num; i<ofline; i++) {
                       fprev();
               }
               
       if (maxfline & num>maxfline) goto bad;
       
       return;

bad:    error("Not that many lines in file");
       ffind(ofline);
}

/* Go back n lines. */
fback(n) {
       int i;
       
       if (nolines){
               return(0);
       }
       for (i=0; i<n; i++) {
               if (fline == 1) return(i);
               fprev();
       }
       return(i);
}

/* Go forwards n lines. */
fforward(n) {
       int i;
       
       if (nolines){
               return(0);
       }
       for (i=0; i<n; i++) {
               fnext();
               if (fline == 1) {
                       fprev();
                       return(i);
               }
       }
       return(i);
}

/* Print n lines. */
fprintn(n) {
       int i;
       
       if (nolines){
               error("No lines in file");
               return(0);
       }
       for (i=0; i<n; i++) {
               fprint();
               fnext();
               if (fline == 1) break;
       }
       fprev();
       return(i);
}