I moved this to the "junkdrawer" repo because I am now using it!

digressions/.gitignore

@@ -1,2 +1 @@
 /temperatures
-/truncpwd

digressions/Makefile

@@ -1,5 +1,5 @@
 CFLAGS += -g -Wall -Wextra
 
-all: temperatures truncpwd
+all: temperatures
 
 .PHONY: all

digressions/truncpwd.c

@@ -1,76 +0,0 @@
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <unistd.h>
-
-
-#define BUFSIZE 2048 + 1
-#define DEFAULT_TRUNCPWD_LEN "40"
-
-
-void substr(char *dest, char *src, int offset, int len) {
-    int i;
-    for (i = 0; i < len && src[offset + i] != '\0'; i++) {
-        dest[i] = src[offset + i];
-    }
-    dest[i] = '\0';
-}
-
-
-void with_home_as_tilde(char *dest, char *src, char *home) {
-    size_t src_len = strlen(src);
-    size_t home_len = strlen(home);
-
-    if (strncmp(src, home, home_len) == 0) {
-        char less_home[BUFSIZE];
-        substr(less_home, src, home_len, src_len - home_len);
-        sprintf(dest, "~%s", less_home);
-    } else {
-        sprintf(dest, "%s", src);
-    }
-}
-
-
-int main(void)
-{
-    char pwd[BUFSIZE];
-    const char *home = getenv("HOME");
-    const char *truncpwd_len_str = getenv("TRUNCPWD_LEN");
-    if (truncpwd_len_str == NULL) {
-        truncpwd_len_str = DEFAULT_TRUNCPWD_LEN;
-    }
-    unsigned int truncpwd_len = (unsigned int)atoi(truncpwd_len_str);
-
-    const char *truncpwd_leader = getenv("TRUNCPWD_LEADER");
-    if (truncpwd_leader == NULL) {
-        truncpwd_leader = "...";
-    }
-
-    if (getcwd(pwd, sizeof(pwd)) == NULL) {
-        fprintf(stderr, "truncpwd: %s\n", strerror(errno));
-        return 1;
-    }
-
-    size_t pwd_len = strlen(pwd);
-
-    if (strncmp(home, pwd, pwd_len) == 0) {
-        printf("~\n");
-    }
-
-    char tilde_subbed[BUFSIZE];
-    with_home_as_tilde(tilde_subbed, pwd, (char *)home);
-
-    size_t tilde_subbed_len = strlen(tilde_subbed);
-
-    if (tilde_subbed_len <= truncpwd_len) {
-        printf("%s\n", tilde_subbed);
-        return 0;
-    } else {
-        char last_n[truncpwd_len + 1];
-        int offset = tilde_subbed_len - truncpwd_len + 1;
-        substr(last_n, tilde_subbed, offset, truncpwd_len + 1);
-        printf("%s%s\n", truncpwd_leader, last_n);
-    }
-    return 0;
-}