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Simplify/improve compareString()

A .h should include only the .h files it needs for a stand-alone compilation. A .c file likewise the .h files for a stand alone compilation, yet some extra .h files are not an issue and do provide collision detection.

Additional soapbox:
I wish the standard C library offered a simple <std.h> that included everything. We waste much time crafting .c files to include just the right ones and detect collisions. Compilers then readily can pre-compile one standard header. Some IDEs offer a tool to set these.

Simplify/improve compareString()

Review .h include needs

Do not rely on other code to include the files for a given .c, .h file.

set.h needs <stdio.h> for FILE.
set.h needs TBD for Pair.
get.h needs <time.h> for time_t.
get.h does not need <stdlib>.
set.c should include "set.h", first.

Simplify/imporve compareString()

int compareString(const char* a, const char* b) {
  int cmp = strncmp(a,b, 2);
  if (cmp < 0) return 1;
  if (cmp > 0) return 2;
  return 0;
}

Perhaps re-write calling code to use strncmp() result directly?

Wrong use of strncpy()

Code uses strncpy() to prevent overrun, yet risks failing to form a string.

char command[10];
strncpy(command, argv[1], 10);  // BAD as `command` may now lack a null character

snprintf(command, sizeof command, "%s", argv[1]); is better.
Good compilers will emit efficient code.

Even this lacks error reporting.

I'd write a helper function for this as program arguments can be quite wild.

Something like:

char *my_strcpy(size_t sz, char dest[sz], char *source) {
  if (strlen(source) >= sz) {
    fprintf(stderr, "Destination buffer size [%zu] too small for <%s>.\n",
        sz, source);
    exit(EXIT_FAILURE);
  }
  return strcpy(dest, source);
}

Review .h include needs

Do not rely on other code to include the files for a given .c, .h file.

set.h needs <stdio.h> for FILE.
set.h needs TBD for Pair.
get.h needs <time.h> for time_t.
get.h does not need <stdlib.h>.
set.c should include "set.h", first.

Simplify/improve compareString()

int compareString(const char* a, const char* b) {
  int cmp = strncmp(a,b, 2);
  if (cmp < 0) return 1;
  if (cmp > 0) return 2;
  return 0;
}

Perhaps re-write calling code to use strncmp() result directly?

Wrong use of strncpy()

Code uses strncpy() to prevent overrun, yet risks failing to form a string.

char command[10];
strncpy(command, argv[1], 10);  // BAD as `command` may now lack a null character

snprintf(command, sizeof command, "%s", argv[1]); is better.
Good compilers will emit efficient code.

Even this lacks error reporting.

I'd write a helper function for this as program arguments can be quite wild.

Something like:

char *my_strcpy(size_t sz, char dest[sz], char *source) {
  if (strlen(source) >= sz) {
    fprintf(stderr, "Destination buffer size [%zu] too small for <%s>.\n",
        sz, source);
    exit(EXIT_FAILURE);
  }
  return strcpy(dest, source);
}

Avoid naked magic number

// Add
#define TIME_BUF_YMDHMS_SZ 50

// char buf[50];
char buf[TIME_BUF_YMDHMS_SZ];

struct tm *ts = localtime(&time);
// strftime(buf, 50, "%Y-%m-%d %H:%M:%S", ts);
strftime(buf, sizeof buf, "%Y-%m-%d %H:%M:%S", ts);

With error checking:

#define TIME_YMDHMS_FMT "%Y-%m-%d %H:%M:%S"
#define TIME_BUF_YMDHMS_SZ (sizeof TIME_YMDHMS_FMT + 6 * 11/* typical longest int string */)

char buf[TIME_BUF_YMDHMS_SZ];

struct tm *ts = localtime(&time);
if (ts == NULL) {
  TBD_handle_error();
} 
if (strftime(buf, sizeof buf, TIME_YMDHMS_FMT, ts) == 0) {
  TBD_handle_error();
} 

Review .h include needs

Do not rely on other code to include the files for a given .c, .h file.

set.h needs <stdio.h> for FILE.
set.h needs TBD for Pair.
get.h needs <time.h> for time_t.
get.h does not need <stdlib>.
set.c should include "set.h", first.

Simplify/imporve compareString()

int compareString(const char* a, const char* b) {
  int cmp = strncmp(a,b, 2);
  if (cmp < 0) return 1;
  if (cmp > 0) return 2;
  return 0;
}

Perhaps re-write calling code to use `strncmp() result directly?

Review .h include needs

Do not rely on other code to include the files for a given .c, .h file.

set.h needs <stdio.h> for FILE.
set.h needs TBD for Pair.
get.h needs <time.h> for time_t.
get.h does not need <stdlib>.
set.c should include "set.h", first.

Simplify/imporve compareString()

int compareString(const char* a, const char* b) {
  int cmp = strncmp(a,b, 2);
  if (cmp < 0) return 1;
  if (cmp > 0) return 2;
  return 0;
}

Perhaps re-write calling code to use strncmp() result directly?

Wrong use of strncpy()

Code uses strncpy() to prevent overrun, yet risks failing to form a string.

char command[10];
strncpy(command, argv[1], 10);  // BAD as `command` may now lack a null character

snprintf(command, sizeof command, "%s", argv[1]); is better.
Good compilers will emit efficient code.

Even this lacks error reporting.

I'd write a helper function for this as program arguments can be quite wild.

Something like:

char *my_strcpy(size_t sz, char dest[sz], char *source) {
  if (strlen(source) >= sz) {
    fprintf(stderr, "Destination buffer size [%zu] too small for <%s>.\n",
        sz, source);
    exit(EXIT_FAILURE);
  }
  return strcpy(dest, source);
}