From 1bf8a67c114568b307c1df6dfe2042e2a3eab49b Mon Sep 17 00:00:00 2001
From: "Andrew J. Schorr" <aschorr@telemetry-investments.com>
Date: Tue, 22 Jun 2021 13:45:25 -0400
Subject: Add isnumeric function.

---
 doc/gawk.texi | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'doc/gawk.texi')

diff --git a/doc/gawk.texi b/doc/gawk.texi
index 2478cf98..fb71bb68 100644
--- a/doc/gawk.texi
+++ b/doc/gawk.texi
@@ -808,6 +808,8 @@ particular records in a file and perform operations upon them.
                                         once.
 * Shell Quoting::                       A function to quote strings for the
                                         shell.
+* Isnumeric Function::                  A function to test whether a value
+                                        is numeric.
 * Data File Management::                Functions for managing command-line
                                         data files.
 * Filetrans Function::                  A function for handling data file
@@ -22462,6 +22464,7 @@ programming use.
 * Getlocaltime Function::       A function to get formatted times.
 * Readfile Function::           A function to read an entire file at once.
 * Shell Quoting::               A function to quote strings for the shell.
+* Isnumeric Function::          A function to test whether a value is numeric.
 @end menu
 
 @node Strtonum Function
@@ -23252,6 +23255,35 @@ function shell_quote(s,             # parameter
 @c endfile
 @end example
 
+@node Isnumeric Function
+@subsection Checking whether a value is numeric
+
+A frequent programming question is how to ascertain whether a value is numeric.
+This can be solved by using this example function @code{isnumeric()}, which
+employs the trick of converting a string value to user input by using the
+@code{split()} function:
+
+@cindex @code{isnumeric()} user-defined function
+@cindex user-defined @subentry function @subentry @code{isnumeric()}
+@example
+@c file eg/lib/isnumeric.awk
+# isnumeric --- check whether a value is numeric
+
+function isnumeric(x,  f)
+@{
+	switch (typeof(x)) @{
+	case "strnum":
+	case "number":
+		return 1
+	case "string":
+		return (split(x, f, " ") == 1) && (typeof(f[1]) == "strnum")
+	default:
+		return 0
+	@}
+@}
+@c endfile
+@end example
+
 @node Data File Management
 @section @value{DDF} Management
 
-- 
cgit v1.2.3


From 98ef29fdcadffc0a05c91883c4ab8809a8b0d441 Mon Sep 17 00:00:00 2001
From: "Arnold D. Robbins" <arnold@skeeve.com>
Date: Wed, 23 Jun 2021 20:30:13 +0300
Subject: More doc updates.

---
 doc/gawk.texi | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

(limited to 'doc/gawk.texi')

diff --git a/doc/gawk.texi b/doc/gawk.texi
index fb71bb68..0372897f 100644
--- a/doc/gawk.texi
+++ b/doc/gawk.texi
@@ -23256,7 +23256,7 @@ function shell_quote(s,             # parameter
 @end example
 
 @node Isnumeric Function
-@subsection Checking whether a value is numeric
+@subsection Checking Whether A Value Is Numeric
 
 A frequent programming question is how to ascertain whether a value is numeric.
 This can be solved by using this example function @code{isnumeric()}, which
@@ -23271,16 +23271,21 @@ employs the trick of converting a string value to user input by using the
 
 function isnumeric(x,  f)
 @{
-	switch (typeof(x)) @{
-	case "strnum":
-	case "number":
-		return 1
-	case "string":
-		return (split(x, f, " ") == 1) && (typeof(f[1]) == "strnum")
-	default:
-		return 0
-	@}
+    switch (typeof(x)) @{
+    case "strnum":
+    case "number":
+        return 1
+    case "string":
+        return (split(x, f, " ") == 1) && (typeof(f[1]) == "strnum")
+    default:
+        return 0
+    @}
 @}
+
+Please note that leading or trailing white space is disregarded in deciding
+whether a value is numeric or not, so if it matters to you, you may want
+to add an additional check for that.
+
 @c endfile
 @end example
 
@@ -24155,8 +24160,8 @@ $ @kbd{awk -f getopt.awk -v _getopt_test=1 -- -a \}
 @print{} c = <otherd>, Optarg = <>
 @print{} c = <otherc>, Optarg = <>
 @print{} non-option arguments:
-@print{} 	ARGV[8] = <arg1>
-@print{} 	ARGV[9] = <arg2>
+@print{}        ARGV[8] = <arg1>
+@print{}        ARGV[9] = <arg2>
 @end example
 
 In all the runs, the first @option{--} terminates the arguments to
@@ -26353,7 +26358,7 @@ look nice on the page:
 @end ignore
 @c file eg/prog/split.awk
 
-function usage(		common)
+function usage(     common)
 @{
     common = "[-a suffix-len] [file [outname]]"
     printf("usage: split [-l count]  %s\n", common) > "/dev/stderr"
@@ -30186,7 +30191,7 @@ main(void)
         printf("%d\n", x + y); 
     return 0; 
 @} 
-$ @kbd{cc -O add.c -o add}	@ii{Compile the program}
+$ @kbd{cc -O add.c -o add}      @ii{Compile the program}
 @end example
 
 You could then write an exceedingly simple @command{gawk} program
-- 
cgit v1.2.3