Code cleanup+documentation

5 files changed, 207 insertions, 155 deletions

diff --git a/Makefile b/Makefile
index 080b44f..bcfa271 100644
--- a/Makefile
+++ b/Makefile
@@ -7,10 +7,10 @@ build:
 	-mkdir build
 	
 bin/cdf: build src/cdf.c include/cdf.h
-	gcc -std=c23 -Iinclude src/cdf.c -o bin/cdf 
+	clang -std=c2x -Iinclude src/cdf.c -o bin/cdf 
 
 bin/cumsum: src/cumsum.c include/cumsum.h
-	gcc -std=c23 -Iinclude src/cumsum.c -o bin/cumsum
+	clang -std=c2x -Iinclude src/cumsum.c -o bin/cumsum
 
 .PHONY: clean
 clean:
diff --git a/doc/cdf.1 b/doc/cdf.1
new file mode 100644
index 0000000..06f3a49
--- /dev/null
+++ b/doc/cdf.1
@@ -0,0 +1,106 @@
+.\" Copyright (c) 2025
+.\" Manual page for cdf(1)
+.\"
+.Dd $Mdocdate$
+.Dt CDF 1
+.Os
+.Sh NAME
+.Nm cdf
+.Nd calculate cumulative distribution function from count data
+.Sh SYNOPSIS
+.Nm cdf
+.Op Fl f | u
+.Op Fl r
+.Op Fl h
+.Op Ar file
+.Sh DESCRIPTION
+The
+.Nm
+utility computes cumulative distribution functions from input data consisting
+of value-count pairs. It reads data from
+.Ar file
+or standard input if no file is specified, calculates relative frequencies,
+and outputs probability-value pairs suitable for statistical analysis and
+plotting.
+.Pp
+Input data must consist of whitespace-separated pairs where the first field
+is the count (frequency) and the second field is the data value. Output
+consists of cumulative probability values followed by the corresponding data
+values, separated by tabs.
+.Pp
+.Sh OPTIONS
+.Bl -tag -width Ds
+.It Fl f
+Read input values as floats.
+.It Fl u
+Read input values as unsigned integers
+.It Fl r
+Generate the complementary cumulative distribution function (CCDF),
+which is P(X > x) = 1 - F(x).
+.It Fl h
+Display usage information and exit.
+.El
+.Pp
+If
+.Fl f
+or
+.Fl u
+is not specified, the input values will be read as signed integers by
+default.
+.Sh INPUT FORMAT
+Each input line must contain exactly two whitespace-separated fields:
+.Bd -literal -offset indent
+count value
+.Ed
+.Pp
+Where
+.Em count
+is a positive integer representing the frequency of occurrence, and
+.Em value
+is the data point.
+.Pp
+Example input:
+.Bd -literal -offset indent
+15  1.25
+23  2.30
+8   3.75
+.Ed
+.Pp
+This format was selected to be compatible with the output of the uniq -c command.
+.Sh EXIT STATUS
+.Ex -std
+.Sh EXAMPLES
+Calculate CDF from integer data in a file:
+.Bd -literal -offset indent
+$ cdf data.txt
+0.300000000000000   10
+0.650000000000000   15
+1.000000000000000   20
+.Ed
+.Pp
+Generate complementary CDF in a pipeline:
+.Bd -literal -offset indent
+$ awk '{print $2, $1}' measurements.dat | cdf -r -f
+1.000000000000000   1.234000
+0.750000000000000   2.567000
+0.400000000000000   4.890000
+.Ed
+.Pp
+Use standard tools for pre-processing:
+.Bd -literal -offset indent
+$ sort -n data.txt | uniq -c | cdf > dist.cdf
+.Ed
+.Sh SEE ALSO
+.Xr sort 1 ,
+.Xr uniq 1 ,
+.Xr gnuplot 1
+.Sh AUTHORS
+.An Douglas B. Rumbaugh
+.Mt "dbrumbaugh@harrisburgu.edu"
+.Sh BUGS
+The program must materialize the full file in order to calculate
+the frequency table. It currently does this in memory, and so very
+large datasets may lead to crashes due to memory allocation failures
+when RAM is limited.
+
+
diff --git a/include/cdf.h b/include/cdf.h
index 418ffeb..956e630 100644
--- a/include/cdf.h
+++ b/include/cdf.h
@@ -7,7 +7,6 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
-#include <ctype.h>
 #include <getopt.h>
 #include <string.h>
 #include <stdint.h>
diff --git a/src/cdf.c b/src/cdf.c
index 45b8fb7..3bf39fe 100644
--- a/src/cdf.c
+++ b/src/cdf.c
@@ -1,8 +1,7 @@
 /*
- * 
+ *
  */
 
-
 #include "cdf.h"
 
 /*
@@ -14,35 +13,36 @@ static bool ARG_FP_INPUT = false;
 static bool ARG_UINT_INPUT = false;
 static bool ARG_HELP = false;
 
-static int parse_options(int argc, char*const* argv) {
+static int parse_options(int argc, char *const *argv) {
   int arg_index = 0;
   int arg;
   bool error = false;
 
   while ((arg = getopt(argc, argv, "frhu")) != -1) {
     switch (arg) {
-      case 'f':
-        ARG_FP_INPUT = true;
-        break;
-      case 'r':
-        ARG_REVERSE_CDF = true;
-        break;
-      case 'u':
-        ARG_UINT_INPUT = true;
-      case 'h':
-        ARG_HELP = true;
-        break;
-      case '?':
-        if (isprint(optopt)) {
-          fprintf(stderr, "Unknown option `-%c`.\n", optopt);
-        } else {
-          fprintf(stderr, "Unknown option character `\\x%x`.\n", optopt);
-        }
-        error = true;
-        break;
-      default:
-        error = true;
-        break;
+    case 'f':
+      ARG_FP_INPUT = true;
+      break;
+    case 'r':
+      ARG_REVERSE_CDF = true;
+      break;
+    case 'u':
+      ARG_UINT_INPUT = true;
+      break;
+    case 'h':
+      ARG_HELP = true;
+      break;
+    case '?':
+      if (isprint(optopt)) {
+        fprintf(stderr, "Unknown option `-%c`.\n", optopt);
+      } else {
+        fprintf(stderr, "Unknown option character `\\x%x`.\n", optopt);
+      }
+      error = true;
+      break;
+    default:
+      error = true;
+      break;
     }
   }
 
@@ -58,13 +58,11 @@ static int parse_options(int argc, char*const* argv) {
   return arg_index;
 }
 
-static void help() {
-  fprintf(stderr, "Usage:\ncdf [-f|-u] [-r] [filename]\n");
-}
+static void help() { fprintf(stderr, "Usage:\ncdf [-f|-u] [-r] [filename]\n"); }
 
 static DistRecord *expand_array(DistRecord *records, size_t *capacity) {
   (*capacity) *= 2;
-  DistRecord *new = realloc(records, (*capacity*sizeof(DistRecord)));
+  DistRecord *new = realloc(records, (*capacity * sizeof(DistRecord)));
   if (!new) {
     fprintf(stderr, "ERROR: Memory allocation failed\n");
     return nullptr;
@@ -73,42 +71,26 @@ static DistRecord *expand_array(DistRecord *records, size_t *capacity) {
   return new;
 }
 
-static int read_data_int(DistRecord **records, size_t capacity, FILE *file) {
-  size_t reccnt = 0;
-  while (fscanf(file, "%ld %ld\n", &(*records + reccnt)->count,
-                &(*records + reccnt)->data.i) != EOF) {
-
-    reccnt++;
-    if (reccnt == capacity) {
-      if (!(*records = expand_array(*records, &capacity))) {
-        return -1;
-      }
-    }
+static int parse_line(DistRecord *record, char *line) {
+  if (ARG_FP_INPUT) {
+    return sscanf(line, "%lld %lf", &record->count, &record->data.d);
+  } else if (ARG_UINT_INPUT) {
+    return sscanf(line, "%lld %llu", &record->count, &record->data.u);
+  } else {
+    return sscanf(line, "%lld %lld", &record->count, &record->data.i);
   }
-
-  return reccnt;
 }
 
-static int read_data_fp(DistRecord **records, size_t capacity, FILE *file) {
+static ssize_t read_data(DistRecord **records, size_t capacity, FILE *file) {
   size_t reccnt = 0;
-  while (fscanf(file, "%ld %lf\n", &(*records + reccnt)->count,
-                &(*records + reccnt)->data.d) != EOF) {
+  char *line = nullptr;
+  size_t line_len = 0;
 
-    reccnt++;
-    if (reccnt == capacity) {
-      if (!(*records = expand_array(*records, &capacity))) {
-        return -1;
-      }
+  while (getline(&line, &line_len, file) != -1) {
+    if (parse_line(*records + reccnt, line) != 2) {
+      fprintf(stderr, "[W] Skipping invalid input line: %s\n", line);
+      continue;
     }
-  }
-
-  return reccnt;
-}
-
-static int read_data_uint(DistRecord **records, size_t capacity, FILE *file) {
-  size_t reccnt = 0;
-  while (fscanf(file, "%ld %ld\n", &(*records + reccnt)->count,
-                &(*records + reccnt)->data.u) != EOF) {
 
     reccnt++;
     if (reccnt == capacity) {
@@ -121,50 +103,27 @@ static int read_data_uint(DistRecord **records, size_t capacity, FILE *file) {
   return reccnt;
 }
 
-static int print_data_fp(DistRecord *records, long double *freqs, size_t cnt) {
-  if (ARG_REVERSE_CDF) {
-    long double total_freq = 1.0;
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%lf\n", total_freq, records[i].data.d);
-      total_freq -= freqs[i];
-    }
-    
+static void print_record(long double freq, DistRecord *record) {
+  if (ARG_FP_INPUT) {
+    fprintf(stdout, "%.15Lf\t%lf\n", freq, record->data.d);
+  } else if (ARG_UINT_INPUT) {
+    fprintf(stdout, "%.15Lf\t%llu\n", freq, record->data.u);
   } else {
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%lf\n", freqs[i], records[i].data.d);
-    }  
+    fprintf(stdout, "%.15Lf\t%lld\n", freq, record->data.i);
   }
-
-  return 1;
 }
 
-static int print_data_int(DistRecord *records, long double *freqs, size_t cnt) {
+static int print_data(DistRecord *records, long double *freqs, size_t cnt) {
   if (ARG_REVERSE_CDF) {
     long double total_freq = 1.0;
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%ld\n", total_freq, records[i].data.i);
+    for (size_t i = 0; i < cnt; i++) {
+      print_record(total_freq, records + i);
       total_freq -= freqs[i];
     }
   } else {
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%ld\n", freqs[i], records[i].data.i);
-    }  
-  }
-
-  return 1;
-}
-
-static int print_data_uint(DistRecord *records, long double *freqs, size_t cnt) {
-  if (ARG_REVERSE_CDF) {
-    long double total_freq = 1.0;
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%ld\n", total_freq, records[i].data.u);
-      total_freq -= freqs[i];
+    for (size_t i = 0; i < cnt; i++) {
+      print_record(freqs[i], records + i);
     }
-  } else {
-    for (size_t i=0; i<cnt; i++) {
-      fprintf(stdout, "%.15Lf\t%ld\n", freqs[i], records[i].data.u);
-    }  
   }
 
   return 1;
@@ -172,22 +131,17 @@ static int print_data_uint(DistRecord *records, long double *freqs, size_t cnt)
 
 static int process_data(FILE *file) {
   int rc = 1;
-  
+
   size_t reccap = 100;
-  DistRecord *records = malloc(reccap*sizeof(DistRecord));
+  DistRecord *records = malloc(reccap * sizeof(DistRecord));
 
-  ssize_t cnt;
-  /* FIXME: this could probably use a type-based macro to collapse the 
-            if statements into a single macro call
-   */
-  if (ARG_FP_INPUT) {
-    cnt = read_data_fp(&records, reccap, file);
-  } else if (ARG_UINT_INPUT) {
-    cnt = read_data_uint(&records, reccap, file);
-  } else {
-    cnt = read_data_int(&records, reccap, file);
+  if (!records) {
+    rc = 0;
+    goto process_data_end;
   }
 
+  ssize_t cnt = read_data(&records, reccap, file);
+
   /* propogate the error */
   if (cnt == -1) {
     rc = 0;
@@ -196,7 +150,7 @@ static int process_data(FILE *file) {
 
   /* calculate total sum of counts */
   uint64_t total_count = 0;
-  for (size_t i=0; i<cnt; i++) {
+  for (size_t i = 0; i < cnt; i++) {
     total_count += records[i].count;
   }
 
@@ -207,18 +161,12 @@ static int process_data(FILE *file) {
     goto free_freqs;
   }
 
-  for (size_t i=0; i<cnt; i++) {
-    freqs[i] = (long double) (records[i].count) / (long double) (total_count);
+  for (size_t i = 0; i < cnt; i++) {
+    freqs[i] = (long double)(records[i].count) / (long double)(total_count);
   }
 
-  if (ARG_FP_INPUT) {
-    rc = print_data_fp(records, freqs, cnt);
-  } else if (ARG_UINT_INPUT) {
-    rc = print_data_uint(records, freqs, cnt);
-  } else {
-    rc = print_data_int(records, freqs, cnt);
-  }
-  
+  rc = print_data(records, freqs, cnt);
+
 free_freqs:
   free(freqs);
 
@@ -229,7 +177,6 @@ process_data_end:
   return rc;
 }
 
-
 int main(int argc, char **argv) {
   int rc = EXIT_SUCCESS;
   int file_index = 0;
@@ -249,7 +196,8 @@ int main(int argc, char **argv) {
   FILE *input_file;
   if (file_index < argc && strcmp(argv[file_index], "-") != 0) {
     if (!(input_file = fopen(argv[file_index], "r"))) {
-      fprintf(stderr, "Error: Unable to open input file %s\n", argv[file_index]);
+      fprintf(stderr, "Error: Unable to open input file %s\n",
+              argv[file_index]);
       rc = EXIT_FAILURE;
       goto program_exit;
     }
@@ -262,7 +210,9 @@ int main(int argc, char **argv) {
   }
 
 close_file:
-  fclose(input_file);
+  if (input_file != stdin) {
+    fclose(input_file);
+  }
 
 program_exit:
   exit(rc);
diff --git a/src/cumsum.c b/src/cumsum.c
index 5648661..268a548 100644
--- a/src/cumsum.c
+++ b/src/cumsum.c
@@ -1,8 +1,7 @@
 /*
- * 
+ *
  */
 
-
 #include "cumsum.h"
 
 /*
@@ -13,32 +12,32 @@ static bool ARG_FP_INPUT = false;
 static bool ARG_UINT_INPUT = false;
 static bool ARG_HELP = false;
 
-static int parse_options(int argc, char*const* argv) {
+static int parse_options(int argc, char *const *argv) {
   int arg_index = 0;
   int arg;
   bool error = false;
 
   while ((arg = getopt(argc, argv, "frhu")) != -1) {
     switch (arg) {
-      case 'f':
-        ARG_FP_INPUT = true;
-        break;
-      case 'u':
-        ARG_UINT_INPUT = true;
-      case 'h':
-        ARG_HELP = true;
-        break;
-      case '?':
-        if (isprint(optopt)) {
-          fprintf(stderr, "Unknown option `-%c`.\n", optopt);
-        } else {
-          fprintf(stderr, "Unknown option character `\\x%x`.\n", optopt);
-        }
-        error = true;
-        break;
-      default:
-        error = true;
-        break;
+    case 'f':
+      ARG_FP_INPUT = true;
+      break;
+    case 'u':
+      ARG_UINT_INPUT = true;
+    case 'h':
+      ARG_HELP = true;
+      break;
+    case '?':
+      if (isprint(optopt)) {
+        fprintf(stderr, "Unknown option `-%c`.\n", optopt);
+      } else {
+        fprintf(stderr, "Unknown option character `\\x%x`.\n", optopt);
+      }
+      error = true;
+      break;
+    default:
+      error = true;
+      break;
     }
   }
 
@@ -54,17 +53,15 @@ static int parse_options(int argc, char*const* argv) {
   return arg_index;
 }
 
-static void help() {
-  fprintf(stderr, "Usage:\ncumsum [-f|-u] [filename]\n");
-}
+static void help() { fprintf(stderr, "Usage:\ncumsum [-f|-u] [filename]\n"); }
 
 void print_sum(Number sum) {
   if (ARG_FP_INPUT) {
     fprintf(stdout, "%lf\n", sum.d);
   } else if (ARG_UINT_INPUT) {
-    fprintf(stdout, "%ld\n", sum.u);
+    fprintf(stdout, "%lld\n", sum.u);
   } else {
-    fprintf(stdout, "%ld\n", sum.i);
+    fprintf(stdout, "%lld\n", sum.i);
   }
 }
 
@@ -79,7 +76,7 @@ static int read_data_fp(FILE *file, Number *num) {
 
 static int read_data_int(FILE *file, Number *num) {
   int64_t val;
-  while (fscanf(file, "%ld ", &val) != EOF) {
+  while (fscanf(file, "%lld ", &val) != EOF) {
     num->i += val;
   }
 
@@ -88,7 +85,7 @@ static int read_data_int(FILE *file, Number *num) {
 
 static int read_data_uint(FILE *file, Number *num) {
   uint64_t val;
-  while (fscanf(file, "%ld ", &val) != EOF) {
+  while (fscanf(file, "%lld ", &val) != EOF) {
     num->u += val;
   }
 
@@ -97,10 +94,10 @@ static int read_data_uint(FILE *file, Number *num) {
 
 static int process_data(FILE *file) {
   int rc = 1;
-  
+
   Number sum = {};
 
-  /* FIXME: this could probably use a type-based macro to collapse the 
+  /* FIXME: this could probably use a type-based macro to collapse the
             if statements into a single macro call
    */
   if (ARG_FP_INPUT) {
@@ -119,7 +116,6 @@ process_data_end:
   return rc;
 }
 
-
 int main(int argc, char **argv) {
   int rc = EXIT_SUCCESS;
   int file_index = 0;
@@ -139,7 +135,8 @@ int main(int argc, char **argv) {
   FILE *input_file;
   if (file_index < argc && strcmp(argv[file_index], "-") != 0) {
     if (!(input_file = fopen(argv[file_index], "r"))) {
-      fprintf(stderr, "Error: Unable to open input file %s\n", argv[file_index]);
+      fprintf(stderr, "Error: Unable to open input file %s\n",
+              argv[file_index]);
       rc = EXIT_FAILURE;
       goto program_exit;
     }