add option for height offset fix #67

completion/_catimg

@@ -40,6 +40,7 @@ _arguments \
   '-c[convert colors to a restricted palette]' \
   '-h[display a help message]' \
   '-H[specify the height of the displayed image]' \
+  '-o[specify the height offset of the displayed image]' \
   '-l[specify the amount of loops that catimg should repeat a GIF]' \
   '-r[force the resolution of the image]: :->resolution' \
   '-t[disable true color and use 256 color instead]' \

man/catimg.1

@@ -5,7 +5,7 @@ catimg \- fast image printing in to your terminal
 
 .SH SYNOPSIS
 .B catimg
-[\fB-hct\fP] [\fB-w width\fP | \fB-H height\fP] [\fB-l loops\fP] [\fB-r resolution\fP] image
+[\fB-hct\fP] [\fB-w width\fP | \fB-H height\fP] [\fB-o height offset\fP] [\fB-l loops\fP] [\fB-r resolution\fP] image
 
 .SH DESCRIPTION
 .B catimg
@@ -22,6 +22,9 @@ Prints a help message
 \fB\-H\fR HEIGHT
 Specify the height of the displayed image, passing '0' will use terminal height.
 .TP
+\fB\-o\fR HEIGHT_OFFSET
+Specify the height offset of the displayed image, passing '0' will use no terminal height offset.
+.TP
 \fB\-l\fR LOOPS
 Specify the amount of loops that catimg should repeat a GIF. A value of 1 means that the GIF will be displayed twice. A negative value implies infinity.
 .TP

src/catimg.c

@@ -11,6 +11,7 @@
   "  -h: Displays this message\n"                                      \
   "  -w: Terminal width/columns by default\n"                           \
   "  -H: Terminal height/row by default\n"                           \
+  "  -o: Terminal height offset by default 1\n"                           \
   "  -l: Loops are only useful with GIF files. A value of 1 means that the GIF will " \
   "be displayed twice because it loops once. A negative value means infinite " \
   "looping\n"                                                           \
@@ -72,13 +73,14 @@ int main(int argc, char *argv[])
     opterr = 0;
 
     uint32_t cols = 0, rows = 0, precision = 0;
+    uint32_t height_offset = 1; // To account for the prompt in vertical scaling
     uint32_t max_cols = 0, max_rows = 0;
     uint8_t convert = 0;
     uint8_t true_color = 1;
     uint8_t adjust_to_height = 0, adjust_to_width = 0;
     float scale_cols = 0, scale_rows = 0;
 
-    while ((c = getopt (argc, argv, "H:w:l:r:hct")) != -1)
+    while ((c = getopt (argc, argv, "H:o:w:l:r:hct")) != -1)
         switch (c) {
             case 'H':
                 rows = strtol(optarg, &num, 0);
@@ -90,6 +92,9 @@ int main(int argc, char *argv[])
                 }
                 adjust_to_height = 1;
                 break;
+            case 'o':
+                height_offset = strtol(optarg, &num, 0);
+                break;
             case 'w':
                 cols = strtol(optarg, &num, 0) >> 1;
                 if (adjust_to_height) {
@@ -138,7 +143,7 @@ int main(int argc, char *argv[])
 
     // if precision is 2 we can use the terminal full width/height. Otherwise we can only use half
     max_cols = terminal_columns() / (2 / precision);
-    max_rows = terminal_rows() * precision;
+    max_rows = (terminal_rows() - height_offset) * precision;
 
     if (strcmp(file, "-") == 0) {
         img_load_from_stdin(&img);