yeah i think it has no bugs

5 files changed, 191 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c7c7345
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+timetolocal
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..ac37253
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,26 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -O2 -pipe 
+LDLIBS = 
+TARGET = timetolocal
+SRC = $(wildcard *.c)
+OBJ = $(SRC:src/%.c=obj/%.o)
+PREFIX = /usr/local
+
+all: $(TARGET)
+
+$(TARGET): $(OBJ)
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS) -o $(TARGET) $(OBJ) $(LDLIBS)
+
+install: $(TARGET)
+	install -D $(TARGET) $(DESTDIR)$(PREFIX)/bin/$(notdir $(TARGET))
+
+uninstall:
+	rm -f $(DESTDIR)$(PREFIX)/bin/$(notdir $(TARGET))
+
+obj/%.o: src/%.c
+	@mkdir -p $(@D)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	rm -rf obj/ $(TARGET)
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..49059f4
--- /dev/null
+++ b/README.md
@@ -0,0 +1,21 @@
+# timetolocal
+
+converts a time from a different timezone to your local time.
+
+## Build
+
+    make
+
+## Usage
+
+    ./timetolocal [TIME (24h)] [ZONE]
+
+Example:
+
+    ./timetolocal 7:15 est
+
+Zone names are not case sensitive. abbreviations come from `tztable.h`
+
+## Installing
+
+    sudo make install
diff --git a/timetolocal.c b/timetolocal.c
new file mode 100644
index 0000000..fce07d1
--- /dev/null
+++ b/timetolocal.c
@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <stdlib.h>
+#include "tztable.h"
+
+/*it's not case sensitive
+returns the offset
+returns -1 if it doesn't find it*/
+int findintable(char *what){
+    for(size_t i = 0; i < TZTABLE_LENGHT; i++){
+        if((strcasecmp(what, tz_table[i].zn)) == 0){
+        return tz_table[i].offset; 
+        }
+    }
+return -1; 
+}
+
+davidtime strtimetoint(char *whattimeisit) {
+    davidtime timehoursandminutes = {0, 0};
+
+    if (whattimeisit == NULL)return timehoursandminutes;
+
+    char buf[16];
+    strncpy(buf, whattimeisit, sizeof(buf) - 1);
+    buf[sizeof(buf) - 1] = '\0';
+
+    char *token = strtok(buf, ":");
+    if (token == NULL) return timehoursandminutes;
+    timehoursandminutes.hour = atoi(token);
+
+    token = strtok(NULL, ":");
+    if (token == NULL) return timehoursandminutes;
+    timehoursandminutes.minutes = atoi(token);
+
+    return timehoursandminutes;
+}
+
+int convert(char *timey, char *zone){
+    time_t rawtime = time(NULL);
+    struct tm *ptm = gmtime(&rawtime);
+    
+    ptm->tm_isdst = -1;                
+    time_t gmt = mktime(ptm);
+    int offset = difftime(rawtime, gmt) / 60;
+    //this sould take even daylight savings too, i stole it from stack overflow i've been trying to not use llms to code shit like this
+
+    //tmzn hour --> utc00 --> local time 
+    if(findintable(zone)== -1){
+        return -1;
+    }
+    int zntime = findintable(zone);
+
+    davidtime eugh = strtimetoint(timey); 
+    int zonetimeminutes = (eugh.hour*60)+eugh.minutes;
+    int normalizedminutes = zonetimeminutes+(zntime*-1); //utc00
+
+    int localminutes = (normalizedminutes+offset) % 1440;  
+
+    davidtime finally; 
+    finally.hour = localminutes/60;
+    finally.minutes = localminutes - finally.hour*60;
+    printf("%02d:%02d\n",finally.hour,finally.minutes);
+    return 0; 
+} 
+
+int main (int argc, char **argv){
+
+    if((argc <= 2) || (argc > 3)){
+        printf("%s: usage: %s [TIME (24hs)] [ZONE]\ne.g: %s 7:15 est\n", argv[0], argv[0], argv[0]);
+        exit(0);
+    }
+
+   if(convert(argv [1], argv[2]) == -1){
+        printf("%s: time zone not found, did you write it correctly?\n", argv[0]);
+        return 1;
+   }else return 0;
+}
diff --git a/tztable.h b/tztable.h
new file mode 100644
index 0000000..69408e5
--- /dev/null
+++ b/tztable.h
@@ -0,0 +1,64 @@
+#ifndef TZTABLE_H
+#define TZTABLE_H
+
+#include <stddef.h>
+
+typedef struct davidtime{
+    int hour;
+    int minutes; 
+}davidtime;
+
+//offset is minutes from UTC (there are duplicates so first match wins on a linear scan)
+struct tztable{
+    const char *zn;
+    int offset;
+};
+
+static const struct tztable tz_table[] = {
+    {"ACDT", 630},  {"ACST", 570},  {"ACT", -300},  {"ACT", 480},   {"ACWST", 525},
+    {"ADT", -180},  {"AEDT", 660},  {"AEST", 600},  {"AFT", 270},   {"AKDT", -480},
+    {"AKST", -540}, {"ALMT", 360},  {"AMST", -180}, {"AMT", -240},  {"AMT", 240},
+    {"ANAT", 720},  {"AQTT", 300},  {"ART", -180},  {"AST", 180},   {"AST", -240},
+    {"AWST", 480},  {"AZOST", 0},   {"AZOT", -60},  {"AZT", 240},   {"BNT", 480},
+    {"BIOT", 360},  {"BIT", -720},  {"BOT", -240},  {"BRST", -120}, {"BRT", -180},
+    {"BST", 360},   {"BST", 660},   {"BST", 60},    {"BTT", 360},   {"CAT", 120},
+    {"CCT", 390},   {"CDT", -300},  {"CDT", -240},  {"CEST", 120},  {"CET", 60},
+    {"CHADT", 825}, {"CHAST", 765}, {"CHOT", 480},  {"CHOST", 540}, {"CHST", 600},
+    {"CHUT", 600},  {"CIST", -480}, {"CKT", -600},  {"CLST", -180}, {"CLT", -240},
+    {"COST", -240}, {"COT", -300},  {"CST", -360},  {"CST", 480},   {"CST", -300},
+    {"CVT", -60},   {"CWST", 525},  {"CXT", 420},   {"DAVT", 420},  {"DDUT", 600},
+    {"DFT", 60},    {"EASST", -300},{"EAST", -360}, {"EAT", 180},   {"ECT", -240},
+    {"ECT", -300},  {"EDT", -240},  {"EEST", 180},  {"EET", 120},   {"EGST", 0},
+    {"EGT", -60},   {"EST", -300},  {"FET", 180},   {"FJT", 720},   {"FKST", -180},
+    {"FKT", -240},  {"FNT", -120},  {"GALT", -360}, {"GAMT", -540}, {"GET", 240},
+    {"GFT", -180},  {"GILT", 720},  {"GIT", -540},  {"GMT", 0},     {"GST", -120},
+    {"GST", 240},   {"GYT", -240},  {"HDT", -540},  {"HAEC", 120},  {"HST", -600},
+    {"HKT", 480},   {"HMT", 300},   {"HOVST", 480}, {"HOVT", 420},  {"ICT", 420},
+    {"IDLW", -720}, {"IDT", 180},   {"IOT", 360},   {"IRDT", 270},  {"IRKT", 480},
+    {"IRST", 210},  {"IST", 330},   {"IST", 60},    {"IST", 120},   {"JST", 540},
+    {"KALT", 120},  {"KGT", 360},   {"KOST", 660},  {"KRAT", 420},  {"KST", 540},
+    {"LHST", 630},  {"LHST", 660},  {"LINT", 840},  {"MAGT", 720},  {"MART", -570},
+    {"MAWT", 300},  {"MDT", -360},  {"MET", 60},    {"MEST", 120},  {"MHT", 720},
+    {"MIST", 660},  {"MIT", -570},  {"MMT", 390},   {"MSK", 180},   {"MST", 480},
+    {"MST", -420},  {"MUT", 240},   {"MVT", 300},   {"MYT", 480},   {"NCT", 660},
+    {"NDT", -150},  {"NFT", 660},   {"NOVT", 420},  {"NPT", 345},   {"NST", -210},
+    {"NT", -210},   {"NUT", -660},  {"NZDT", 780},  {"NZDST", 780}, {"NZST", 720},
+    {"OMST", 360},  {"ORAT", 300},  {"PDT", -420},  {"PET", -300},  {"PETT", 720},
+    {"PGT", 600},   {"PHOT", 780},  {"PHT", 480},   {"PHST", 480},  {"PKT", 300},
+    {"PMDT", -120}, {"PMST", -180}, {"PONT", 660},  {"PST", -480},  {"PWT", 540},
+    {"PYST", -180}, {"PYT", -240},  {"RET", 240},   {"ROTT", -180}, {"SAKT", 660},
+    {"SAMT", 240},  {"SAST", 120},  {"SBT", 660},   {"SCT", 240},   {"SDT", -600},
+    {"SGT", 480},   {"SLST", 330},  {"SRET", 660},  {"SRT", -180},  {"SST", -660},
+    {"SYOT", 180},  {"TAHT", -600}, {"THA", 420},   {"TFT", 300},   {"TJT", 300},
+    {"TKT", 780},   {"TLT", 540},   {"TMT", 300},   {"TRT", 180},   {"TOT", 780},
+    {"TST", 480},   {"TVT", 720},   {"ULAST", 540}, {"ULAT", 480},  {"UTC", 0},
+    {"UYST", -120}, {"UYT", -180},  {"UZT", 300},   {"VET", -240},  {"VLAT", 600},
+    {"VOLT", 180},  {"VOST", 360},  {"VUT", 660},   {"WAKT", 720},  {"WAST", 120},
+    {"WAT", 60},    {"WEST", 60},   {"WET", 0},     {"WIB", 420},   {"WIT", 540},
+    {"WITA", 480},  {"WGST", -120}, {"WGT", -180},  {"WST", 480},   {"YAKT", 540},
+    {"YEKT", 300},
+};
+
+#define TZTABLE_LENGHT (sizeof(tz_table) / sizeof(tz_table[0]))
+
+#endif