diff options
Diffstat (limited to 'just.c')
| -rw-r--r-- | just.c | 295 |
1 files changed, 295 insertions, 0 deletions
@@ -0,0 +1,295 @@ +/* program for text justification */ + +/************************************************************************** + * Copyright (C) Research Software Limited 1985-90. All rights reserved. * + * The Miranda system is distributed as free software under the terms in * + * the file "COPYING" which is included in the distribution. * + * * + * Revised to C11 standard and made 64bit compatible, January 2020 * + *------------------------------------------------------------------------*/ + +/* usage: just [-<width>] [-t<tolerance>] [file...] + if no files given uses standard input. Default width is 72. + 1) blank lines remain blank. + 2) if a line begins with blanks, these are preserved and it is not + merged with the previous one. + 3) lines which begin with more than THRESHOLD (currently 7) spaces + or have a '>' in column 1, have their layout frozen. + otherwise each line is merged with the following lines and reformatted so + as to maximise the number of words in the line and justify it to the + specified width. Justification is not performed on a line however if + it would require the insertion of more than tolerance (default 3) + extra spaces in any one place. +*/ + +/* now handles tabs ok - if you change THRESHOLD, see warning in getln */ + +#include <stdio.h> +#include <stdlib.h> +#include <ctype.h> +#define MAXBUF 3600 +#define MAXWIDTH 2400 +#define THRESHOLD 7 +int tolerance=3; + /* the largest insert of extra spaces we are willing to tolerate + in one place */ + +main(argc,argv) +int argc; +char *argv[]; +{ int width=72; + FILE *j_in=fopen(".justwidth","r"); + if(j_in){ if(fscanf(j_in,"%d",&width)!=1)width=72; + fclose(j_in); } + while(argc>1&&argv[1][0]=='-') + if(argv[1][1]=='t'&&isdigit(argv[1][2])) + { sscanf(argv[1]+2,"%d",&tolerance); + argc--; argv++; + }else + if(isdigit(argv[1][1])||argv[1][1]=='-'&&isdigit(argv[1][2])) + { sscanf(argv[1]+1,"%d",&width); + argc--; argv++; + } + else fprintf(stderr,"just: unknown flag %s\n",argv[1]),exit(1); + if(width<0)width = -width, tolerance=0; + if(width==0)width=MAXWIDTH, tolerance=0; + if(width<6||width>MAXWIDTH) + { fprintf(stderr,"just: silly width %d\n",width); + fprintf(stderr,"(legal widths are in the range 6 to %d)\n",MAXWIDTH); + exit(1); + } + if(argc==1)justify(width,stdin,"input"); else + while(--argc>0) + { FILE *fp=fopen(*++argv,"r"); + if(fp==NULL) + { fprintf(stderr,"just: cannot open %s\n",*argv); + break; + } + else justify(width,fp,*argv); + } + exit(0); +} + +static char buf[MAXBUF+2],*bp=buf; + +#include <string.h> +#define index(s,c) strchr(s,c) + +int linerr=0; + +justify(width,fp,fn) +int width; +FILE *fp; +char *fn; +{ int c=' '; /* c initialised to anything != EOF */ + int worderr=0,w; + /*if(fp==stdin)setbuf(fp,NULL); /* to fix weird bug when "just" used in + pipeline - DT 15/1/85 */ + /* note - above has disastrous effect on system time used, for large + inputs, therefore switched off 19/2/87 - fortunately bug seems to be + fixed in 4.2 BSD */ + linerr=0; + while(c!=EOF&&(c=getc(fp))!=EOF) + /* 1st part of test needed because ungetc(EOF,fp) ineffective */ + if(c=='\f')putchar('\f');else /* formfeed counts as blank line */ + { ungetc(c,fp); + getln(fp,0); + if(bp==buf||buf[0]=='>'||indent(buf)>THRESHOLD) /* blank or frozen line */ + { puts(bp=buf); continue; } + /*otherwise perform justification up to next indented,blank or frozen line*/ + squeeze(buf); + while(bp-buf>(w=width+bs_cor(buf))||!isspace(c=peek(fp))&&c!=EOF&&c!='>') + if(bp-buf<=w/*idth+bs_cor(buf)*/) + { pad(); getln(fp,1); } + else{ /* cut off as much as you can use */ + char *rp = &buf[width]; + { char *sp=index(buf,'\b'); /* correction for backspaces */ + while(sp&&sp<=rp)rp += 2, sp=index(sp+1,'\b'); } + while(*rp!=' ' && rp>buf)rp--; /* searching for word break */ + if(rp==buf) + { worderr=1; + while(rp-buf<width-1)putchar(*rp++); /* print width-1 chars */ + putchar('-'); /* to signify forced word break */ + putchar('\n'); + } + else { while(rp[-1]==' '||rp[-1]=='\b'&&rp[-2]=='_') + rp -= rp[-1]==' '?1:2; /* find start of break */ + if(*rp=='_'&&rp[1]=='\b'&&rp[2]==' ')rp += 2; + /* leave trace of underlined gap */ + while((*rp==' ' + ||*rp=='_'&&rp[1]=='\b'&&rp[2]==' ' + ||*rp=='\b'&&rp[1]==' ') + &&rp<bp)*rp++ = '\0'; /* find end of break */ + rjust(buf,width); + } + /* shuffle down what's left */ + strcpy(buf,rp); + bp -= rp-buf; + } + puts(bp=buf); + } + if(worderr) + fprintf(stderr, + "just: warning -- %s contained words too big for line\n",fn); + if(linerr) + fprintf(stderr, + "just: warning -- %s contained disastrously long lines\n",fn); +} + +getln(fp,crush) +FILE *fp; +int crush; +{ char *lose=fgets(bp,MAXBUF-MAXWIDTH+(buf-bp),fp); + if(index(bp,'\t')&&indent(bp)<=THRESHOLD&&bp[0]!='>') + { /* line contains tabs and is not frozen */ + char *p; + while(p=index(bp,'\t'))*p=' '; /* replace each tab by one space */ + /* WARNING - if THRESHOLD:=8 or greater, will need to change this to + handle leading tabs more carefully, expanding each to right number + of spaces, to preserve indentation */ + /* at the moment, however, any line containing tabs in its indentation + will be frozen anyway */ + } + bp += strlen(bp); + if(bp[-1]=='\n')*--bp='\0'; + else + { /* amendment to cope with arbitrarily long input lines: + if no newline found, break at next beginning-of-word */ + int c; + while((c=getc(fp))!=EOF&&!isspace(c)&&bp-buf<MAXBUF)*bp++ = c; + if(c==EOF||c=='\n')*bp='\0'; else + if(bp-buf==MAXBUF) /* give up! */ + { linerr = 1; + *bp++ = '\\'; /* to signify forced break */ + *bp = '\0'; } else + { *bp++ = ' '; + while((c=getc(fp))==' '||c=='\t'); + if(c!=EOF&&c!='\n')ungetc(c,fp); + *bp = '\0'; } + } + /* remove trailing blanks */ + while(bp[-1]==' '&&!(bp[-2]=='\b'&&bp[-3]=='_'))*--bp='\0'; + /* eliminate all but one underlined trailing space */ + if(crush) + while(bp[-1]==' '&&bp[-2]=='\b'&&bp[-3]=='_'&& + bp[-4]==' '&&bp[-5]=='\b'&&bp[-6]=='_')bp -= 3,*bp='\0'; + if(crush) + squeeze(buf); +} + +indent(s) /* size of white space at front of s */ +char *s; +{ int i=0; + while(*s==' '||*s=='\t') + if(*s++ == ' ')i++; + else i = 8*(1+i/8); + return(i); +} + +#define istermch(c) ((c)=='.'||(c)=='?'||(c)=='!') + +squeeze(s) /* remove superfluous blanks between words */ +char *s; +{ char *t; + int eosen; + /* if(1){ bp=s+strlen(s); return; } /* temporary measure to isolate bugs */ + t = s = s + indent(s); + for(;;) + { while(*t&&*t!=' '&&!(*t=='_'&&t[1]=='\b'&&t[2]==' '))*s++ = *t++; + eosen= istermch(t[-1]); + *s++ = *t; + if(*t=='\0')break; + if(*t==' ') + { if(eosen&&t[1]==' ')*s++ = ' '; /* upto one extra space after + sentence terminator is preserved */ + while(*++t==' '); /* eat unnecessary spaces */ } + else + { /* deal with underlined spaces */ + *s++ = '\b'; *s++ = ' '; + if(eosen&&t[3]=='_'&&t[4]=='\b'&&t[5]==' ') + *s++ = '_', *s++ = '\b', *s++ = ' '; /* xta space after termch */ + t += 3; + while(t[0]=='_'&&t[1]=='\b'&&t[2]==' ')t += 3; } + } + bp=s-1; +} + +peek(fp) +FILE *fp; +{ int c=getc(fp); + ungetc(c,fp); + return(c); +} + +rjust(s,width) /* print s justified to width */ +char *s; +int width; +{ int gap=width-strlen(s)+bs_cor(s),wc=words(s)-1; + int i,r; + static leftist=0; /* bias for odd spaces when r>0 */ + char *printword(); + if(wc)i=gap/wc,r=gap%wc; + if(wc==0||i+(r>0)>tolerance){char *t=s+strlen(s); + fputs(s,stdout); + if(t[-1]=='\b'&&t[-2]=='_')putchar(' '); + putchar('\n'); + return;}else + if(leftist) + for(;;) + { s=printword(s); + if(!*s)break; + spaces(i+(r-- >0),s[0]=='_'&&s[1]=='\b'&&s[2]==' '); + } + else + { r = wc-r; + for(;;) + { s=printword(s); + if(!*s)break; + spaces(i+(r-- <=0),s[0]=='_'&&s[1]=='\b'&&s[2]==' '); + } + } + leftist = !leftist; + putchar('\n'); +} + +pad() /* insert space(s) if necessary when joining two lines */ +{ if(bp[-1]!=' ')*bp++ = ' '; + if(istermch(bp[-2]))*bp++ = ' '; else + if(bp[-1]==' '&&bp[-2]=='\b'&&bp[-3]=='_' + &&istermch(bp[-4]))*bp++ = '_', *bp++ = '\b', *bp++ = ' '; +} + +spaces(n,ul) +int n,ul; +{ while(n--)if(ul)printf("_\b "); + else putchar(' '); +} + +words(s) /* counts words (naively defined) in s */ +char *s; +{ int c=0; + while(*s) + if(*s++!=' '&&s[-1]!='\b'&&(*s==' '|| *s=='_'&&s[1]=='\b'&&s[2]==' '))c++; + return(c+1); +} + +char *printword(s) /* prints a word preceded by any leading spaces and + returns remainder of s */ +char *s; +{ while(s[0]=='_'&&s[1]=='\b'&&s[2]==' ') /* underlined spaces */ + putchar(*s++),putchar(*s++),putchar(*s++); + while(*s==' ')putchar(*s++); + while(*s&&*s!=' '&&!(*s=='_'&&s[1]=='\b'&&(s[2]==' '||s[2]=='\0'))) + putchar(*s++); + if(s[0]=='_'&&s[1]=='\b'&&s[2]=='\0')s++,s++,printf("_\b "); + /* restore trailing underlined space */ + return(s); +} + +bs_cor(s) /* correction to length due to backspaces in string s */ +char *s; +{ int n=0; + while(*s++)if(s[-1]=='\b')n += 2; + if(s[-1]=='\0'&&s[-2]=='\b'&&s[-3]=='_')n--; /* implied space before \0 */ + return(n); +} |