9cb00c4f07c40b647094f0d03b2bcce00e535d9c
kent
  Thu Dec 31 14:56:48 2020 -0800
Added hashTsvBy since I needed it in two places, and it seems pretty general, but not common.

diff --git src/lib/obscure.c src/lib/obscure.c
index f6bea35..609e321 100644
--- src/lib/obscure.c
+++ src/lib/obscure.c
@@ -156,30 +156,58 @@
 struct lineFile *lf = lineFileOpen(fileName, TRUE);
 struct hash *hash = hashNew(16);
 char *row[3];
 int fields = 0;
 while ((fields = lineFileChop(lf, row)) != 0)
     {
     lineFileExpectWords(lf, 2, fields);
     char *name = row[0];
     char *value = lmCloneString(hash->lm, row[1]);
     hashAdd(hash, name, value);
     }
 lineFileClose(&lf);
 return hash;
 }
 
+struct hash *hashTsvBy(char *in, int keyColIx, int *retColCount)
+/* Return a hash of rows keyed by the given column */
+{
+struct lineFile *lf = lineFileOpen(in, TRUE);
+struct hash *hash = hashNew(0);
+char *line = NULL, **row = NULL;
+int colCount = 0, colAlloc=0;	/* Columns as counted and as allocated */
+while (lineFileNextReal(lf, &line))
+    {
+    if (colCount == 0)
+        {
+	*retColCount = colCount = chopByChar(line, '\t', NULL, 0);
+	verbose(2, "Got %d columns in first real line\n", colCount);
+	colAlloc = colCount + 1;  // +1 so we can detect unexpected input and complain 
+	lmAllocArray(hash->lm, row, colAlloc);
+	}
+    int count = chopByChar(line, '\t', row, colAlloc);
+    if (count != colCount)
+        {
+	errAbort("Expecting %d words, got more than that line %d of %s", 
+	    colCount, lf->lineIx, lf->fileName);
+	}
+    hashAdd(hash, row[keyColIx], lmCloneRow(hash->lm, row, colCount) );
+    }
+lineFileClose(&lf);
+return hash;
+}
+
 struct slPair *slPairTwoColumnFile(char *fileName)
 /* Read in a two column file into an slPair list */
 {
 char *row[2];
 struct slPair *list = NULL;
 struct lineFile *lf = lineFileOpen(fileName, TRUE);
 while (lineFileRow(lf, row))
     slPairAdd(&list, row[0], cloneString(row[1]));
 lineFileClose(&lf);
 slReverse(&list);
 return list;
 }
 
 struct slName *readAllLines(char *fileName)
 /* Read all lines of file into a list.  (Removes trailing carriage return.) */