---
name: "Concat"
section: "3tcl"
platform: "linux"
package: "tcl8.3-doc"
version: "8.3.5-13"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/Concat/3tcl"
---

# Concat(3tcl)

concatenate a collection of strings

```

```

## NAME

Tcl\_Concat - concatenate a collection of strings

## SYNOPSIS

```
#include <tcl.h>

char *
Tcl_Concat(argc, argv)
```

## ARGUMENTS

- int *argc* (in)

  Number of strings.

- char *\*argv\[\]* (in)

  Array of strings to concatenate.  Must have *argc* entries.

  ```

  ```

## DESCRIPTION

**Tcl\_Concat** is a utility procedure used by several of the Tcl commands.  Given a collection of strings, it concatenates them together into a single string, with the original strings separated by spaces.  This procedure behaves differently than **Tcl\_Merge**, in that the arguments are simply concatenated: no effort is made to ensure proper list structure. However, in most common usage the arguments will all be proper lists themselves;  if this is true, then the result will also have proper list structure.

**Tcl\_Concat** eliminates leading and trailing white space as it copies strings from **argv** to the result.  If an element of **argv** consists of nothing but white space, then that string is ignored entirely.  This white-space removal was added to make the output of the **concat** command cleaner-looking.

The result string is dynamically allocated using **Tcl\_Alloc**;  the caller must eventually release the space by calling **Tcl\_Free**.

## SEE ALSO

Tcl\_ConcatObj

## KEYWORDS

concatenate, strings