/* $Copyright:	$
 * Copyright (c) 1984, 1985, 1986, 1987, 1988, 1989, 1990 
 * Sequent Computer Systems, Inc.   All rights reserved.
 *  
 * This software is furnished under a license and may be used
 * only in accordance with the terms of that license and with the
 * inclusion of the above copyright notice.   This software may not
 * be provided or otherwise made available to, or used by, any
 * other person.  No title to or ownership of the software is
 * hereby transferred.
 */

/*
 *                     RCS checkin operation
 */
 static char rcsid[]= "$Header: ci.c 3.13 90/08/06 $ Purdue CS";
/*******************************************************************
 *                       check revisions into RCS files
 *******************************************************************
 *
 * Copyright (C) 1982 by Walter F. Tichy
 *                       Purdue University
 *                       Computer Science Department
 *                       West Lafayette, IN 47907
 *
 * All rights reserved. No part of this software may be sold or distributed
 * in any form or by any means without the prior written permission of the
 * author.
 * Report problems and direct all inquiries to Tichy@purdue (ARPA net).
 */



/* $Log:	ci.c,v $
 */

#include "rcsbase.h"
static char rcsbaseid[] = RCSBASE;
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>

extern int short_header;	       /*true if you want short headers	    */
extern int    rename();                /*rename files                       */
extern struct passwd *getpwuid();
extern struct hshentry * genrevs();    /*generate delta numbers             */
extern int  nextc;                     /*next input character               */
extern quietflag;                      /*suppresses diagnostics if true     */
extern int  nerror;                    /*counter for errors                 */
extern char * buildrevision();         /* constructs desired revision       */
extern char * checkid();               /*check identifiers                  */
extern char * getdate();               /*formates current date  (forward)   */
extern char * mktempfile();            /*temporary file name generator      */
extern struct lock * addlock();        /*adds a new lock                    */
extern char * getlogmsg();             /* obtains log message; forward      */
extern struct hshentry * removelock(); /*finds a caller's lock  (forward)   */
extern char * xpandfile();             /* perform keyword expansion; forward*/

extern char prevauthor[];
extern char prevdate[];
extern char prevrev[];
extern char prevstate [];
extern FILE * finptr;                  /* RCS input file                    */
extern FILE * frewrite;                /* new RCS file                      */

char * RCSfilename,*workfilename,*expfilename,*newworkfilename;
char * newRCSfilename, * diffilename;


int    rewriteflag; /* indicates whether input should be echoed to frewrite */
int    copyflag;    /* indicates whether a string should be copied into memory*/

char * rev, * state, *msg;

int initflag, rcsinitflag;
int lockflag, keepworkingfile,keepflag;
int forceciflag;                      /* forces check in                    */
int symrebindflag; char * symbol;
int textflag; char * textfile;
char * caller;                        /* caller's login;                    */
struct hshentry * targetdelta;        /* old delta to be generated          */
char   * olddeltanum;                 /* number of old delta                */
struct hshentry * gendeltas[hshsize]; /* stores deltas to be generated      */
char   newdelnum[revlength];          /* holds new revision number          */
int    newdnumlength;                 /* actual length of new rev. num.     */
char   branchpointnum[revlength];     /* number of branchpoint              */
struct hshentry newdelta;             /* new delta to be inserted           */
struct branchhead newbranch;          /* new branch to be inserted          */
char   logmsg[logsize];               /* buffer for log message             */

main (argc, argv)
int argc;
char * argv[];
{
        register int i;
        register char * sp, *tp;
        char * cmdusage;         /* holds command format                    */
        char command[NCPPN+50];  /* holds diff commands                     */
        char curdate[datelength];/* date for new delta                      */
        struct stat filestatus;  /* used for getting the mode               */
        int  msglen;             /* length of message given by -m           */
        int exit_stats;          /* return code for system() calls          */

	catchints();
        cmdid = "ci";
        cmdusage = "command format:\nci -r[rev] -l[rev] -u[rev] -f[rev] -k[rev] -q[rev] -mmsg -nname -Nname -sstate -t[txtfile] file ...";
        rev = state = msg = symbol = textfile = caller = nil;
        initflag= rcsinitflag= symrebindflag= textflag= quietflag= false;
        forceciflag= lockflag= keepworkingfile= keepflag= false;
        caller=getpwuid(getuid())->pw_name;

        while (--argc,++argv, argc>=1 && ((*argv)[0] == '-')) {
                switch ((*argv)[1]) {

                case 'r':
                        lockflag=false;
                revno:  if ((*argv)[2]!='\0') {
                                if (rev!=nil) warn("Redefinition of revision number");
                                rev = (*argv)+2;
                        }
                        break;

                case 'l':
                        keepworkingfile=lockflag=true;
                        goto revno;

                case 'u':
                        keepworkingfile=true; lockflag=false;
                        goto revno;

                case 'q':
                        quietflag=true;
                        goto revno;

                case 'f':
                        forceciflag=true;
                        goto revno;

                case 'k':
                        keepflag=true;
                        goto revno;

                case 'm':
                        if ((*argv)[2]!='\0'){
                                if (msg!=nil)warn("Redefinition of -m option");
                                msg = (*argv)+2;
                                msglen=strlen(msg);
                                if (msglen >= logsize) {
                                   warn("log message truncated to %d characters",
                                        logsize);
                                   msg[logsize-2]='\n';
                                   msg[logsize-1]='\0';
                                }
                                if (msg[msglen-1]!='\n') {
                                   /*append linefeed*/
                                   strcpy(logmsg,msg);msg=logmsg;
                                   msg[msglen]  = '\n';
                                   msg[++msglen]= '\0';
                                }
                        } else warn("Missing message for -m option");
                        break;

                case 'n':
                        symrebindflag=false;
                        if ((*argv)[2]!='\0'){
                                if (symbol!=nil)warn("Redefinition of symbolic name");
                                symbol = (*argv)+2;
                                checkid(symbol,' ');
                        } else warn("Missing name for -n option");
                        break;

                case 'N':
                        symrebindflag=true;
                        if ((*argv)[2]!='\0'){
                                if (symbol!=nil)warn("Redefinition of symbolic name");
                                symbol = (*argv)+2;
                                checkid(symbol,' ');
                        } else warn("Missing name for -N option");
                        break;

                case 's':
                        if ((*argv)[2]!='\0'){
                                if (state!=nil)warn("Redefinition of -s option");
                                state = (*argv)+2;
                                checkid(state,' ');
                        } else warn("Missing state for -s option");
                        break;

                case 't':
                        textflag=true;
                        if ((*argv)[2]!='\0'){
                                if (textfile!=nil)warn("Redefinition of -t option");
                                textfile = (*argv)+2;
                        }
                        break;
		case 'S':
			short_header = true;
			break;

                default:
                        faterror("unknown option: %s\n%s", *argv,cmdusage);
                };
        }  /* end processing of options */

        if (argc<1) faterror("No input file\n%s",cmdusage);

        if (!isatty(fileno(stdin)) && msg==nil && textflag && textfile==nil) {
                /* would need both log message and descriptive text from a file */
                faterror("Can't take both log and description from redirected stdin; use -ttextfile");
        }
        /* now handle all filenames */
        do {
        gendeltas[0] = nil;
        copyflag=rewriteflag=false;
        finptr=frewrite=NULL;
        targetdelta=nil;
        olddeltanum=nil;

        switch (pairfilenames(argc,argv,false,false)) {

        case -1:                /* New RCS file */
                initflag=true; rcsinitflag=false;
                break;

        case 0:                 /* Error */
                continue;

        case 1:                 /* Normal checkin with prev . RCS file */
                initflag=false; rcsinitflag=(Head==nil);
        }

        /* now RCSfilename contains the name of the RCS file, and
         * workfilename contains the name of the working file.
         * if !initflag, finptr contains the file descriptor for the
         * RCS file. The admin node is initialized.
         */

        diagnose("%s  <--  %s", RCSfilename,workfilename);

        if (access(workfilename,4)!=0) {
                error("working file %s not readable or nonexistent",
                       workfilename);
                continue;
        }

        if (initflag || rcsinitflag) /* get mode for RCSfile from workfile*/
            stat(workfilename, &filestatus);
        else /* otherwise keep the one from the RCS file.*/
            fstat(fileno(finptr), &filestatus);

        if (!trydiraccess(RCSfilename)) continue; /* give up */
        if (!initflag && !checkaccesslist(caller))   continue; /* give up */
        if (!trysema(RCSfilename,true)) continue; /* give up */

        if (keepflag) {
                /* get keyword values from working file */
                if (!getoldkeys(workfilename)) continue;
                if (rev==nil && *(rev=prevrev)=='\0') {
                        error("Can't find a revision number in %s",workfilename);
                        continue;
                }
                if (*prevdate=='\0') {
                        error("Can't find a date in %s",workfilename);
                        continue;
                }
                if (*prevauthor=='\0')
                        warn("Can't find an author in %s", workfilename);
                if (*prevstate=='\0')
                        warn("Can't find a state in %s", workfilename);
        } /* end processing keepflag */

        gettree(); /* reads in the delta tree.*/

        /* expand symbolic revision number */
        if (!expandsym(rev,newdelnum)) continue;
        newdnumlength=countnumflds(newdelnum);

        if (initflag || rcsinitflag ) {
                /* this covers non-existing RCS file and a file initialized with rcs -i */
                if (newdnumlength==0) strcpy(newdelnum,"1.1");
                elsif (newdnumlength==1) strcat(newdelnum,".1");
                elsif (newdnumlength>2) {
                        error("Branch point does not exist for %s",
                        newdelnum);
                        continue;
                } /* newdnumlength == 2 is OK;  */
                olddeltanum=nil;
                Head = &newdelta;
                newdelta.next=nil;
        } elsif (newdnumlength==0) {
                /* derive new revision number from locks */
                if(!(targetdelta=removelock(caller,nil))) continue;
                olddeltanum=targetdelta->num;
                if (!genrevs(olddeltanum,nil,nil,nil,gendeltas)) continue;

                if (targetdelta==Head) {
                        /* make new head */
                        newdelta.next=Head;
                        Head= &newdelta;
                        incnum(olddeltanum, newdelnum);
                } elsif ((targetdelta->next==nil)&&(countnumflds(olddeltanum)>2)) {
                        /* new tip revision on side branch */
                        targetdelta->next= &newdelta;
                        newdelta.next = nil;
                        incnum(olddeltanum, newdelnum);
                } else {
                        /* middle revision; start a new branch */
                        newdelnum[0]='\0';
                        if (!addbranch(targetdelta,newdelnum)) continue;
                }

        } elsif (newdnumlength<=2) {
                /* add new head per given number */
                /* put new revision on trunk */
                olddeltanum=Head->num;
                if(newdnumlength==1) {
                        /* make a two-field number out of it*/
                        if (cmpnumfld(newdelnum,olddeltanum,1)==0)
                                incnum(olddeltanum,newdelnum);
                        else    strcat(newdelnum, ".1");
                }
                if (cmpnum(newdelnum,olddeltanum) <= 0) {
                        error("deltanumber %s too low; must be higher than %s",
                              newdelnum,Head->num);
                        continue;
                }
                if (!(targetdelta=removelock(caller,Head))) continue;
                if (!(genrevs(olddeltanum,nil,nil,nil,gendeltas))) continue;
                newdelta.next=Head;
                Head= &newdelta;

        } else {
                /* put new revision on side branch */
                /*first, get branch point */
                tp=branchpointnum; sp=newdelnum;
                for(i=newdnumlength-(newdnumlength%2==1?1:2);i>0;i--) {
                        while (*sp != '.') *tp++ = *sp++; /*copy field*/
                        *tp++ = *sp++;                    /*copy dot  */
                }
                *(tp-1) = '\0'; /* kill final dot */
                olddeltanum=branchpointnum; /*temporary old delta*/
                if (!(targetdelta=genrevs(branchpointnum,nil,nil,nil,gendeltas))) continue;
                if (cmpnum(targetdelta->num,branchpointnum)!=0) {
                        error("Cannot find branchpoint %s",branchpointnum);
                        continue;
                }
                if (!addbranch(targetdelta,newdelnum)) continue;
        }
        if (initflag||rcsinitflag) {
                diagnose("initial revision: %s",newdelnum);
        } else  diagnose("new revision: %s; previous revision: %s",
                newdelnum,olddeltanum);

        newdelta.num=newdelnum;
        newdelta.branches=nil;
        newdelta.log=nil;
        newdelta.lockedby=nil; /*might be changed by addlock() */
        if (!keepflag) {
                newdelta.author=caller;
                newdelta.state =state==nil?DEFAULTSTATE:state;
                newdelta.date  =getdate(curdate);
        } else {
                newdelta.author=(*prevauthor=='\0')?caller:prevauthor;
                newdelta.state =(*prevstate =='\0')?DEFAULTSTATE:prevstate;
                newdelta.date  =prevdate;
                if (newdelta.next!=nil &&
                    cmpnum(prevdate,newdelta.next->date)<=0) {
                        error("Date in %s is older than existing revision %s",
                               workfilename,newdelta.next->num);
                        continue;
                }
        }
        if (lockflag && !addlock(&newdelta,caller)) continue;
        if (symbol && !addsymbol(&newdelta,symbol,symrebindflag)) continue;

        /* prepare for rewriting the RCS file */
        newRCSfilename=mktempfile(RCSfilename,NEWRCSFILE);
        if ((frewrite=fopen(newRCSfilename, "w"))==NULL) {
                error("Can't open file %s",newRCSfilename);
                continue;
        }
        putadmin(frewrite);
        puttree(Head,frewrite);
        putdesc(initflag,textflag,textfile,quietflag);


        /* build rest of file */
        if (initflag||rcsinitflag) {
                /* get logmessage */
                newdelta.log=getlogmsg();
                if(!putdtext(newdelnum,newdelta.log,workfilename,frewrite)) continue;
                ffclose(frewrite); frewrite=NULL;
        } else {
                diffilename=mktempfile("/tmp/",DIFFILE);
                if (&newdelta==Head) {
                        /* prepend new one */
                        rewriteflag=false;
                        if (!(expfilename=
                              buildrevision(gendeltas,targetdelta,"/tmp/",false))) continue;
                        if (!mustcheckin(expfilename,targetdelta)) continue;
                                /* don't check in files that aren't different, unless forced*/
                        newdelta.log=getlogmsg();
                        sprintf(command,"%s -n %s %s > %s\n", DIFF,
                                workfilename,expfilename,diffilename);
                        exit_stats = system (command);
                        if (exit_stats != 0 && exit_stats != (1 << BYTESIZ))
                            faterror ("diff failed");
                        /* diff returns 2 in the upper byte on failure */
                        if(!putdtext(newdelnum,newdelta.log,workfilename,frewrite)) continue;
                        if(!putdtext(olddeltanum,targetdelta->log,diffilename,frewrite)) continue;
                } else {
                        /* insert new delta text */
                        rewriteflag=true;
                        if (!(expfilename=
                              buildrevision(gendeltas,targetdelta,"/tmp/",false))) continue;
                        if (!mustcheckin(expfilename,targetdelta)) continue;
                                /* don't check in files that aren't different, unless forced*/
                        newdelta.log=getlogmsg();
                        sprintf(command,"%s -n %s %s > %s\n", DIFF,
                                expfilename,workfilename,diffilename);
                        exit_stats = system (command);
                        if (exit_stats != 0 && exit_stats != (1 << BYTESIZ))
                            faterror ("diff failed");
                        if(!putdtext(newdelnum,newdelta.log,diffilename,frewrite)) continue;
                }

                /* rewrite rest of RCS file */
                fastcopy(finptr,frewrite);
                ffclose(frewrite); frewrite=NULL;
        }
	ignoreints();
        if (rename(newRCSfilename,RCSfilename)<0) {
                error("Can't write new RCS file %s; saved in %s",
                      RCSfilename,newRCSfilename);
                newRCSfilename[0]='\0'; /* avoid deletion by cleanup*/
		catchints();
                cleanup();
                break;
        }
        newRCSfilename[0]='\0'; /* avoid re-unlinking by cleanup()*/
        if (chmod(RCSfilename,filestatus.st_mode & ~0222)<0)
                warn("Can't set mode of %s",RCSfilename);

	catchints();
#       ifdef SNOOPFILE
        logcommand("ci",&newdelta,gendeltas,caller);
#       endif

        if (!keepworkingfile) {
                unlink(workfilename); /* get rid of old file */
        } else {
                /* expand keywords in file */
                newworkfilename=
                xpandfile(workfilename,workfilename /*for directory*/,&newdelta);
                if (!newworkfilename) continue; /* expand failed */
		ignoreints();
                unlink(workfilename);
                if (link(newworkfilename,workfilename)<0) {
                    error("Can't expand keywords in %s",workfilename);
		    catchints();
                    continue;
                }
                if (chmod(workfilename, WORKMODE(filestatus.st_mode))<0)
                    warn("Can't adjust mode of %s",workfilename);
		catchints();
        }
        diagnose("done");

        } while (cleanup(),
                 ++argv, --argc >=1);

        exit(nerror!=0);
}       /* end of main (ci) */
/*****************************************************************/
/* the rest are auxiliary routines                               */


int addbranch(branchpoint,num)
struct hshentry * branchpoint;
char * num;
/* adds a new branch and branch delta at branchpoint.
 * If num is the null string, appends the new branch, incrementing
 * the highest branch number (initially 1), and setting the level number to 1.
 * the new delta and branchhead are in globals newdelta and newbranch, resp.
 * the new number is placed into num.
 * returns false on error.
 */
{
        struct branchhead * bhead, * btrail;
        char branchnum[revlength];
        int numlength, result, field;

        numlength = countnumflds(num);

        if (branchpoint->branches==nil) {
                /* start first branch */
                branchpoint->branches = &newbranch;
                if (numlength==0) {
                        strcpy(num, branchpoint->num);
                        strcat(num,".1.1");
                } elsif(countnumflds(num)%2 == 1)
                        strcat(num, ".1");
                newbranch.nextbranch=nil;

        } elsif (numlength==0) {
                /* append new branch to the end */
                bhead=branchpoint->branches;
                while (bhead->nextbranch) bhead=bhead->nextbranch;
                bhead->nextbranch = &newbranch;
                getbranchno(bhead->hsh->num,branchnum);
                incnum(branchnum,num);
                strcat(num,".1");
                newbranch.nextbranch=nil;
        } else {
                /* place the branch properly */
                field = numlength - (numlength%2 ==1?0:1);
                /* field of branch number */
                bhead=branchpoint->branches;
                while ((bhead!=nil) &&
                       ((result=cmpnumfld(num,bhead->hsh->num,field))>0)) {
                        btrail=bhead;
                        bhead=bhead->nextbranch;
                }
                if (bhead==nil || result<0) {
                        /* insert/append new branchhead */
                        if (bhead==branchpoint->branches)
                                branchpoint->branches= &newbranch;
                        else    btrail->nextbranch= &newbranch;
                        newbranch.nextbranch=bhead;
                        if (numlength%2 ==1) strcat(num,".1");
                } else {
                        /* branch exists; append to end */
                        getbranchno(num,branchnum);
                        if (!(targetdelta=genrevs(branchnum,nil,nil,nil,gendeltas))) return false;
                        olddeltanum=targetdelta->num;
                        if (cmpnum(num,olddeltanum) <= 0) {
                                error("deltanumber %s too low; must be higher than %s",
                                      num,olddeltanum);
                                return false;
                        }
                        if (!removelock(caller,targetdelta)) return false;
                        if (numlength%2==1) incnum(olddeltanum,num);
                        targetdelta->next= &newdelta;
                        newdelta.next=nil;
                        return true; /* Don't do anything to newbranch */
                }
        }
        newbranch.hsh = &newdelta;
        newdelta.next=nil;
        return true;
}



struct hshentry * removelock(who,delta)
char * who; struct hshentry * delta;
/* function: Finds the lock held by who on delta,
 * removes it, and returns a pointer to the delta.
 * delta may be nil; then the first lock held by who is chosen.
 * Prints an error message and returns nil if there is no such lock.
 * An exception is if StrictLocks==false, and who is the owner of
 * the RCS file. If who does not have a lock in this case,
 * delta is returned (or Head, if delta is nil).
 */
{
        register struct lock * next, * trail;
        char * num;
        struct stat statbuf;
        struct lock dummy;
        int owner, whomatch, nummatch;

        num=(delta==nil)?nil:delta->num;
        dummy.nextlock=next=Locks;
        trail = &dummy;
        while (next!=nil) {
                whomatch=strcmp(who,next->login);
                if (num==nil) {
                        if (whomatch==0) break; /* found a lock by who */
                } else {
                        nummatch=strcmp(num,next->delta->num);
                        if ((whomatch==0) && (nummatch==0)) break;
                                             /*found a lock on delta by who*/
                        if ((whomatch!=0)&&(nummatch==0)) {
                            error("revision %s locked by %s",num,next->login);
                            return false;
                        }
                }
                trail=next;
                next=next->nextlock;
        }
        if (next!=nil) {
                /*found one; delete it */
                trail->nextlock=next->nextlock;
                Locks=dummy.nextlock;
                next->delta->lockedby=nil; /* reset locked-by */
                return next->delta;
        } else {
                fstat(fileno(finptr), &statbuf);
                owner= (StrictLocks==false) && (getuid() == statbuf.st_uid);
                if (!owner) {
                        if (num==nil) error("no lock set by %s",who);
                        else          error("no lock set by %s for revision %s",who,num);
                        return nil;
                } elsif (num!=nil) {
                        return delta;
                } else { /* want to return Head, but check first if locked*/
                        next=Locks; num=Head->num;
                        while (next!=nil) {
                                if (strcmp(num,next->delta->num)==0) {
                                        error("revision %s locked by %s",num,next->login);
                                        return false;
                                }
                                trail=next;
                                next=next->nextlock;
                        }
                        return Head;
                }
        }
}



char * getdate(buffer)
char * buffer;
/* Function: puts the current date in the form
 * YY.MM.DD.hh.mm.ss\0 into buffer and returns a pointer to it.
 */
{
#       include "time.h"

        extern struct tm* localtime();
        extern long time();
        long clock;
        struct tm * tm;
        clock=time(0);
        tm=localtime(&clock);
        sprintf(buffer, DATEFORM,
                tm->tm_year, tm->tm_mon+1, tm->tm_mday,
                tm->tm_hour, tm->tm_min, tm->tm_sec);
        return buffer;
}


char * xpandfile (unexfname,dir,delta)
char * unexfname, * dir;
struct hshentry * delta;
/* Function: Reads file unexpfname and copies it to a
 * file in dir, performing keyword substitution with data from delta.
 * returns the name of the expanded file if successful, nil otherwise.
 */
{       char * targetfname;
        FILE * unexfile, *exfile;

        targetfname=mktempfile(dir,TMPFILE3);
        if ((unexfile=fopen(unexfname,  "r" ))==NULL ||
            (exfile  =fopen(targetfname,"w"))==NULL) {
                error("Can't expand file %s",unexfname);
                return nil;
        }
        while (expandline(unexfile,exfile,delta,false,false)); /*expand*/
        ffclose(unexfile);ffclose(exfile);
        return targetfname;
}


mustcheckin (unexfname,delta)
char * unexfname; struct hshentry * delta;
/* Function: determines whether checkin should proceed.
 * Compares the wrkfilename with unexfname, disregarding keywords.
 * If the 2 files differ, returns true. If they do not differ, asks the user
 * whether to return true or false (i.e., whether to checkin the file anyway.
 * If the files do not differ, and quietflag==true, returns false.
 * Shortcut: If forceciflag==true, mustcheckin() always returns true.
 */
{       register int c;
        int response, result;

        if (forceciflag) return true;

        if (!rcsfcmp(workfilename,unexfname,delta)) return true;
        /* If files are different, must check them in. */

        /* files are the same */
        diagnose("File %s is unchanged with respect to revision %s",
                workfilename,delta->num);
        if (quietflag || !isatty(fileno(stdin))) {
                /* Files are the same, but can't ask, so don't checkin*/
                result=false;
        } else {
                /* ask user whether to check in */
                fputs("checkin anyway? [ny](n): ",stdout);
                response=c=getchar();
                while (!(c==EOF || c=='\n')) c=getchar();/*skip to end of line*/
                result=(response=='y'||response=='Y');
        }
        if (result==false) {
                if (quietflag) {
                    warn("checkin aborted since %s was not changed; %s %sdeleted.",
                             workfilename,workfilename,keepworkingfile?"not ":"");
                } else {
                    diagnose("checkin aborted; %s %sdeleted.",
                             workfilename,keepworkingfile?"not ":"");
                }
                if (!keepworkingfile) unlink(workfilename);
        }
        return result;
}




/* --------------------- G E T L O G M S G --------------------------------*/


char * getlogmsg()
/* Function: obtains a log message and returns a pointer to it.
 * If a log message is given via the -m option, a pointer to that
 * string is returned.
 * If this is the initial revision, a standard log message is returned.
 * Otherwise, reads a character string from the terminal.
 * The string must be terminated with a control-d or a single '.' on a
 * line. getlogmsg prompts the first time it is called for the
 * log message; during all later calls it asks whether the previous
 * log message can be reused.
 * returns a pointer to the character string; the pointer is always non-nil.
 */
{
        static logyet = false;      /*indicates whether previous log present*/
        static char emptylog[]  = "*** empty log message ***\n";
        static char initiallog[]= "Initial revision\n";
        char response;
	int cin;
        register char c, old1, old2, * tp;

        if (msg) return msg;

        if ((olddeltanum==nil)&&
            ((cmpnum(newdelnum,"1.1")==0)||(cmpnum(newdelnum,"1.0")==0)))
                return initiallog;
        if (logyet) {
                /*previous log available*/
                if (!isatty(fileno(stdin))) return logmsg; /* reuse if stdin is not a terminal*/
                /* otherwise ask */
		clearerr(stdin);		/* reset EOF ptr */
                fputs("reuse log message of previous file? [yn](y): ",stdout);
                cin=getchar();
		response=cin;
                while (!(cin==EOF || cin=='\n')) cin=getchar();/*skip to end of line*/
                if (response=='\n'||response=='y'||response=='Y')
                        return logmsg;
                else
                        logmsg[0]='\0'; /*kill existing log message */
        }

        /* now read string from terminal */
        if (isatty(fileno(stdin)))
               fputs("enter log message:\n(terminate with ^D or single '.')\n>> ",stdout);
        tp=logmsg; old1='\n'; old2=' ';
	if (feof(stdin))
		clearerr(stdin);
        for (;;) {
                cin=getchar();
                if (cin==EOF) {
                        if(isatty(fileno(stdin))) putc('\n',stdout);
                        if (*(tp-1) != '\n') *tp++ = '\n'; /* append newline */
                        *tp = '\0'; /*terminate*/
                        break;
                }
                if (cin=='\n' && old1=='.' && old2=='\n') {
                        *(tp-1) = '\0'; /*kill last period */
                        break;
                }
                if (tp>=logmsg+logsize-2) { /* overflow */
                        if (!isatty(fileno(stdin))) {
                                warn("log message truncated to %d characters",logsize);
                                logmsg[logsize-2]='\n';logmsg[logsize-1]='\0';
                                return logmsg;
                        }
                        fprintf(stdout,"log message too long. Maximum: %d\n",logsize);
                        fputs("reenter log message:\n>> ",stdout);
                        tp=logmsg; old1='\n'; old2=' ';
                        while (cin!='\n') cin=getchar(); /*skip line */
                        continue;
                }
                if (cin=='\n' && isatty(fileno(stdin))) fputs(">> ",stdout);
                *tp++ = cin; old2=old1; old1=cin; /* this is the actual work!*/
                /*SDELIM will be changed to double SDELIM by putdtext*/
        } /* end for */

        /* now check whether the log message is not empty */
        tp=logmsg;
        while ((c= *tp++)==' '||c=='\t'||c=='\n'||c=='\f');
        if (*tp=='\0') {
                logyet=false;
                return emptylog;
        } else {
                logyet=true;
                return logmsg;
        }
}
