sortline.c

/*
  Example usage:
  cat /usr/share/dict/words | tr -cd '[:alpha:]\n' | tr '[:lower:]' '[:upper:]' |
    sortline | sort | uniq -c | awk '$1 > 1'

  Compile & install:
  cc -O3 -o sortline sortline.c && install -p sortline ~/bin

  ----------------------------------------------------------------

  Because of the in-place insertion sort specified to bytes, this runs significantly
  faster than the Python script.  Otherwise, because this program is IO-bound,
  I'd expect them to run closer in speed.
*/


#include <stdio.h>
#include <string.h>


/* http://www.cs.auckland.ac.nz/~jmor159/PLDS210/niemann/s_ins.txt */
static void insertSort(char *a, int n) {
  int i;

  for (i = 1; i <= n; i++) {
    int tmp = a[i];
    int j;

    /* Shift elements down until insertion point found. */
    for (j = i - 1; j >= 0 && a[j] > tmp; j--) {
      a[j + 1] = a[j];
    }

    /* insert */
    a[j + 1] = tmp;
  }
}


int main (void) {
  char buf[BUFSIZ];
  while (fgets(buf, sizeof buf, stdin)) {
    int n = (int)strlen(buf);
    while (n > 0 && (buf[n - 1] == '\n' || buf[n - 1] == '\r')) {
      n--;
    }
    if (n > 0) {
      insertSort(buf, n);
    }
    printf("%s", buf);
  }
  return 0;
}

sortline.py

#/usr/bin/env python

# Example usage:
# cat /usr/share/dict/words | tr -cd '[:alpha:]\n' | tr '[:lower:]' '[:upper:]' | sortline.py | sort | uniq -c | awk '$1 > 1'

# Install:
# install -p sortline.py ~/bin

import sys
import fileinput

sys.stdout.writelines(
    ''.join(sorted(line.strip())) + '\n'
    for line in fileinput.input()
)