various little bug fixes
diff --git a/src/cmd/fmt.c b/src/cmd/fmt.c
new file mode 100644
index 0000000..e43731e
--- /dev/null
+++ b/src/cmd/fmt.c
@@ -0,0 +1,241 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <ctype.h>
+
+/*
+ * block up paragraphs, possibly with indentation
+ */
+
+int extraindent = 0; /* how many spaces to indent all lines */
+int indent = 0; /* current value of indent, before extra indent */
+int length = 70; /* how many columns per output line */
+int join = 1; /* can lines be joined? */
+int maxtab = 8;
+Biobuf bin;
+Biobuf bout;
+
+typedef struct Word Word;
+struct Word{
+ int bol;
+ int indent;
+ char text[1];
+};
+
+void fmt(void);
+
+void
+usage(void)
+{
+ fprint(2, "usage: %s [-j] [-i indent] [-l length] [file...]\n", argv0);
+ exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+ int i, f;
+ char *s, *err;
+
+ ARGBEGIN{
+ case 'i':
+ extraindent = atoi(EARGF(usage()));
+ break;
+ case 'j':
+ join = 0;
+ break;
+ case 'w':
+ case 'l':
+ length = atoi(EARGF(usage()));
+ break;
+ default:
+ usage();
+ }ARGEND
+
+ if(length <= indent){
+ fprint(2, "%s: line length<=indentation\n", argv0);
+ exits("length");
+ }
+
+ s=getenv("tabstop");
+ if(s!=nil && atoi(s)>0)
+ maxtab=atoi(s);
+ err = nil;
+ Binit(&bout, 1, OWRITE);
+ if(argc <= 0){
+ Binit(&bin, 0, OREAD);
+ fmt();
+ }else{
+ for(i=0; i<argc; i++){
+ f = open(argv[i], OREAD);
+ if(f < 0){
+ fprint(2, "%s: can't open %s: %r\n", argv0, argv[i]);
+ err = "open";
+ }else{
+ Binit(&bin, f, OREAD);
+ fmt();
+ Bterm(&bin);
+ if(i != argc-1)
+ Bputc(&bout, '\n');
+ }
+ }
+ }
+ exits(err);
+}
+
+int
+indentof(char **linep)
+{
+ int i, ind;
+ char *line;
+
+ ind = 0;
+ line = *linep;
+ for(i=0; line[i]; i++)
+ switch(line[i]){
+ default:
+ *linep = line;
+ return ind;
+ case ' ':
+ ind++;
+ break;
+ case '\t':
+ ind += maxtab;
+ ind -= ind%maxtab;
+ break;
+ }
+
+ /* plain white space doesn't change the indent */
+ *linep = "";
+ return indent;
+}
+
+Word**
+addword(Word **words, int *nwordp, char *s, int l, int indent, int bol)
+{
+ Word *w;
+
+ w = malloc(sizeof(Word)+l+1);
+ memmove(w->text, s, l);
+ w->text[l] = '\0';
+ w->indent = indent;
+ w->bol = bol;
+ words = realloc(words, (*nwordp+1)*sizeof(Word*));
+ words[(*nwordp)++] = w;
+ return words;
+}
+
+Word**
+parseline(char *line, Word **words, int *nwordp)
+{
+ int ind, l, bol;
+
+ ind = indentof(&line);
+ indent = ind;
+ bol = 1;
+ for(;;){
+ /* find next word */
+ while(*line==' ' || *line=='\t')
+ line++;
+ if(*line == '\0'){
+ if(bol)
+ return addword(words, nwordp, "", 0, -1, bol);
+ break;
+ }
+ /* how long is this word? */
+ for(l=0; line[l]; l++)
+ if(line[l]==' ' || line[l]=='\t')
+ break;
+ words = addword(words, nwordp, line, l, indent, bol);
+ bol = 0;
+ line += l;
+ }
+ return words;
+}
+
+void
+printindent(int w)
+{
+ while(w >= maxtab){
+ Bputc(&bout, '\t');
+ w -= maxtab;
+ }
+ while(w > 0){
+ Bputc(&bout, ' ');
+ w--;
+ }
+}
+
+/* give extra space if word ends with period, etc. */
+int
+nspaceafter(char *s)
+{
+ int n;
+
+ n = strlen(s);
+ if(n < 2)
+ return 1;
+ if(isupper(s[0]) && n < 4)
+ return 1;
+ if(strchr(".!?", s[n-1]) != nil)
+ return 2;
+ return 1;
+}
+
+
+void
+printwords(Word **w, int nw)
+{
+ int i, j, n, col, nsp;
+
+ /* one output line per loop */
+ for(i=0; i<nw; ){
+ /* if it's a blank line, print it */
+ if(w[i]->indent == -1){
+ Bputc(&bout, '\n');
+ if(++i == nw) /* out of words */
+ break;
+ }
+ /* emit leading indent */
+ col = extraindent+w[i]->indent;
+ printindent(col);
+ /* emit words until overflow; always emit at least one word */
+ for(n=0;; n++){
+ Bprint(&bout, "%s", w[i]->text);
+ col += utflen(w[i]->text);
+ if(++i == nw)
+ break; /* out of words */
+ if(w[i]->indent != w[i-1]->indent)
+ break; /* indent change */
+ nsp = nspaceafter(w[i-1]->text);
+ if(col+nsp+utflen(w[i]->text) > extraindent+length)
+ break; /* fold line */
+ if(!join && n != 0 && w[i]->bol)
+ break;
+ for(j=0; j<nsp; j++)
+ Bputc(&bout, ' '); /* emit space; another word will follow */
+ col += nsp;
+ }
+ /* emit newline */
+ Bputc(&bout, '\n');
+ }
+}
+
+void
+fmt(void)
+{
+ char *s;
+ int i, nw;
+ Word **w;
+
+ nw = 0;
+ w = nil;
+ while((s = Brdstr(&bin, '\n', 1)) != nil){
+ w = parseline(s, w, &nw);
+ free(s);
+ }
+ printwords(w, nw);
+ for(i=0; i<nw; i++)
+ free(w[i]);
+ free(w);
+}
