Add args

- --pager

include/arg.h

@@ -2,7 +2,7 @@
 #define ARG_H
 #include <stdbool.h>
 
-#define LAT_VERSION "0.9.3"
+#define LAT_VERSION "0.10.0"
 
 struct config {
   bool stdin;
@@ -11,6 +11,7 @@ struct config {
   bool lines;
   bool headers;
   int force_binary;
+  bool pager;
   bool has_read_stdin;
 };
 

src/lib/arg.c

@@ -5,7 +5,7 @@
 #include "arg.h"
 #include "util.h"
 
-#define LAT_USAGE "usage: lat [-cntbVh] [file...]"
+#define LAT_USAGE "usage: lat [-cntbpVh] [file...]"
 
 void help(void) {
   printf("lat | lazy cat - a cat clone with some quality-of-life "
@@ -18,23 +18,27 @@ void help(void) {
          "\t-t, --headers\t toggle whether to print file headers or not\n"
          "\t-b, --binary\t toggle whether to force the data to be treated as "
          "binary or not. see examples\n"
+         "\t-p, --pager\t print file a pager (less)\n"
          "\t-V, --version\t show program version\n"
-         "\t-h, --help\t display this help text\n\n");
+         "\t-h, --help\t display this help text (--help shows additional info)\n\n");
   printf("environment:\n"
          "\tNO_COLOR, see https://no-color.org/\n\n");
+}
+
+void examples(void) {
   printf(
       "examples:\n"
       "\tlat file1\n\t\t print the content of file1 witht default formatting\n"
       "\tlat - file1\n\t\t read from stdin (the '-' character reads from "
       "stdin) "
       "and then print the contents of stdin and file1\n"
-      "\tlat --lines --color file1 file2\n\t\t print the contents of file1 and "
+      "\tlat -nc file1 file2\n\t\t print the contents of file1 and "
       "file2 "
       "without printing line numbers or colors\n"
       "\tlat --binary file.txt\n\t\t force file.txt to be treated as a binary "
       "file\n"
-      "\tlat -bb file.txt\n\t\t force file.txt to NOT be treated as a binary "
-      "file\n"
+      "\tlat -bb --pager file.txt\n\t\t force file.txt to NOT be treated "
+      "as a binary file and print it in the pager\n"
       "\tcurl example.com | lat\n\t\t pipe the results of 'curl example.com' "
       "into lat\n");
 }
@@ -76,8 +80,13 @@ void parselongarg(char *arg) {
     return;
   }
 
+  if (strcmp(arg, "--pager") == 0) {
+    conf.pager = !conf.pager;
+  }
+
   if (strcmp(arg, "--help") == 0) {
     help();
+    examples();
     exit(EXIT_SUCCESS);
     return;
   }
@@ -111,6 +120,9 @@ void parseshortarg(char *arg) {
       else
         conf.force_binary = !conf.force_binary;
       break;
+    case 'p':
+      conf.pager = !conf.pager;
+      break;
     case 'V':
       version();
       exit(EXIT_SUCCESS);

src/main.c

@@ -15,6 +15,9 @@
 #define GREY "\x1b[90m"
 #define RESET "\x1b[0m"
 
+FILE *st;
+FILE *err;
+
 void run(FILE *fp, char *filename, bool tty) {
   const char *invert_t = conf.color ? INVERT_T : "";
   const char *grey = conf.color ? GREY : "";
@@ -23,18 +26,24 @@ void run(FILE *fp, char *filename, bool tty) {
   struct filedata f;
   f = readfile(fp, conf.stdin);
 
+  if (conf.pager) {
+    st = popen("less", "w");
+    err = st;
+
+    if (st == NULL)
+      die("popen 'less'");
+  }
+
   if (conf.force_binary > 0) {
     f.binary = true;
   } else if (conf.force_binary == 0) {
     f.binary = false;
   }
 
-  conf.headers = conf.headers && tty; // tty still overrides user
-
   if (conf.headers) {
     char *addon = f.binary ? "<binary>" : "";
-    fprintf(stderr, "\r\x1b[2K%s%s%s%s\r\n", invert_t, basename(filename),
-            addon, reset);
+    fprintf(err, "\x1b[2K\r%s%s%s%s\r\n", invert_t, basename(filename), addon,
+            reset);
   }
 
   conf.process = (tty && !f.binary);
@@ -47,35 +56,44 @@ void run(FILE *fp, char *filename, bool tty) {
     for (int i = 0; i < f.lc; i++) {
       if (conf.lines) {
         char *padding = linepad(linecount, f.lc);
-        printf("%s%s%d:%s ", grey, padding, i + 1, reset);
-        fwrite(f.lines[i].buf, 1, f.lines[i].len, stdout);
-        printf("\n");
+        fprintf(st, "%s%s%d│%s ", grey, padding, i + 1, reset);
+        fwrite(f.lines[i].buf, 1, f.lines[i].len, st);
+        fprintf(st, "\n");
         free(padding);
         linecount++;
       } else {
-        printf("%s\n", f.lines[i].buf);
+        fprintf(st, "%s\n", f.lines[i].buf);
       }
       free(f.lines[i].buf);
     }
   } else {
-    fwrite(f.buf, 1, f.buflen, stdout);
+    fwrite(f.buf, 1, f.buflen, st);
+    fwrite("\n", 1, 1, err);
   }
   free(f.buf);
 
-  fflush(stdout); // prevent timing inconsistencies between stdout and stderr
+  fflush(st); // prevent timing inconsistencies between st and err
 
   if (conf.headers) {
     float rounded;
     char *format = formatbytes(f.buflen, &rounded);
 
-    fprintf(stderr, "\r%s%.2f %s%s\r\n", invert_t, rounded, format, reset);
+    fprintf(err, "%s%.2f %s%s\r\n", invert_t, rounded, format, reset);
+  }
+
+  if (conf.pager) {
+    pclose(st); // err is already the same as st
+
+    st = stdout;
+    err = stderr;
   }
 }
 
 void initconf(void) {
-  conf.stdin = false;
   conf.force_binary = -1;
+  conf.stdin = false;
   conf.has_read_stdin = false;
+  conf.pager = false;
   conf.process = true;
   conf.headers = true;
   conf.color = true;
@@ -91,6 +109,9 @@ void clearstdin(void) {
 int main(int argc, char *argv[]) {
   initconf();
 
+  st = stdout;
+  err = stderr;
+
   // init no_color first so that args take priority
   char *no_color = getenv("NO_COLOR");
 
@@ -101,6 +122,9 @@ int main(int argc, char *argv[]) {
   bool tty = isatty(STDOUT_FILENO);
   if (argc > 1) {
     int offset = parseargs(argc, argv);
+    conf.headers = conf.headers && tty; // tty still overrides user
+    conf.pager = conf.pager && tty;
+
     for (int i = offset; i < argc; i++) {
       if (*argv[i] == '-') {
         if (conf.has_read_stdin)
@@ -117,9 +141,8 @@ int main(int argc, char *argv[]) {
         die(argv[i]);
       run(fp, argv[i], tty);
       fclose(fp);
-
       if (tty && (i + 1 != argc)) {
-        fprintf(stderr, "\r\n"); // separate concurrent files in tty
+        fprintf(err, "\r\n"); // separate concurrent files in tty
       }
     }